refactor: clear the template cache after uninstalling the theme (#7174)

#### What type of PR is this?
/kind improvement
/area core
/milestone 2.20.x

#### What this PR does / why we need it:
卸载主题之后清理模板缓存

此问题是 #2970 的遗留问题

#### Does this PR introduce a user-facing change?

```release-note
None
```

application/src/main/java/run/halo/app/core/reconciler/ThemeReconciler.java

@@ -10,6 +10,7 @@
 import java.util.Objects;
 import java.util.Set;
 import java.util.UUID;
+import lombok.RequiredArgsConstructor;
 import org.apache.commons.lang3.StringUtils;
 import org.springframework.retry.support.RetryTemplate;
 import org.springframework.stereotype.Component;
@@ -31,6 +32,7 @@
 import run.halo.app.infra.utils.JsonUtils;
 import run.halo.app.infra.utils.SettingUtils;
 import run.halo.app.infra.utils.VersionUtils;
+import run.halo.app.theme.TemplateEngineManager;
 
 /**
  * Reconciler for theme.
@@ -39,27 +41,22 @@
  * @since 2.0.0
  */
 @Component
+@RequiredArgsConstructor
 public class ThemeReconciler implements Reconciler<Request> {
     private static final String FINALIZER_NAME = "theme-protection";
 
     private final ExtensionClient client;
 
     private final ThemeRootGetter themeRoot;
     private final SystemVersionSupplier systemVersionSupplier;
+    private final TemplateEngineManager templateEngineManager;
 
     private final RetryTemplate retryTemplate = RetryTemplate.builder()
         .maxAttempts(20)
         .fixedBackoff(300)
         .retryOn(IllegalStateException.class)
         .build();
 
-    public ThemeReconciler(ExtensionClient client, ThemeRootGetter themeRoot,
-        SystemVersionSupplier systemVersionSupplier) {
-        this.client = client;
-        this.themeRoot = themeRoot;
-        this.systemVersionSupplier = systemVersionSupplier;
-    }
-
     @Override
     public Result reconcile(Request request) {
         client.fetch(Theme.class, request.name())
@@ -173,6 +170,7 @@ private void cleanUpResourcesAndRemoveFinalizer(String themeName) {
     }
 
     private void reconcileThemeDeletion(Theme theme) {
+        templateEngineManager.clearCache(theme.getMetadata().getName()).block();
         deleteThemeFiles(theme);
         // delete theme setting form
         String settingName = theme.getSpec().getSettingName();

application/src/test/java/run/halo/app/core/reconciler/ThemeReconcilerTest.java

@@ -32,10 +32,10 @@
 import org.springframework.retry.RetryException;
 import org.springframework.util.FileSystemUtils;
 import org.springframework.util.ResourceUtils;
+import reactor.core.publisher.Mono;
 import run.halo.app.core.extension.AnnotationSetting;
 import run.halo.app.core.extension.Setting;
 import run.halo.app.core.extension.Theme;
-import run.halo.app.core.reconciler.ThemeReconciler;
 import run.halo.app.extension.ConfigMap;
 import run.halo.app.extension.ExtensionClient;
 import run.halo.app.extension.Metadata;
@@ -44,6 +44,7 @@
 import run.halo.app.infra.SystemVersionSupplier;
 import run.halo.app.infra.ThemeRootGetter;
 import run.halo.app.infra.utils.JsonUtils;
+import run.halo.app.theme.TemplateEngineManager;
 
 /**
  * Tests for {@link ThemeReconciler}.
@@ -66,6 +67,9 @@ class ThemeReconcilerTest {
     @Mock
     private File defaultTheme;
 
+    @Mock
+    private TemplateEngineManager templateEngineManager;
+
     @InjectMocks
     ThemeReconciler themeReconciler;
 
@@ -76,6 +80,7 @@ class ThemeReconcilerTest {
     void setUp() throws IOException {
         defaultTheme = ResourceUtils.getFile("classpath:themes/default");
         lenient().when(systemVersionSupplier.get()).thenReturn(Version.parse("0.0.0"));
+        lenient().when(templateEngineManager.clearCache(any())).thenReturn(Mono.empty());
     }
 
     @Test
@@ -128,7 +133,8 @@ void reconcileDeleteRetry() {
         when(themeRoot.get()).thenReturn(testWorkDir);
 
         final ThemeReconciler themeReconciler =
-            new ThemeReconciler(extensionClient, themeRoot, systemVersionSupplier);
+            new ThemeReconciler(extensionClient, themeRoot, systemVersionSupplier,
+                templateEngineManager);
 
         final int[] retryFlags = {0, 0};
         when(extensionClient.fetch(eq(Setting.class), eq("theme-test-setting")))
@@ -157,6 +163,7 @@ void reconcileDeleteRetry() {
         verify(extensionClient, times(2)).fetch(eq(Theme.class), eq(metadata.getName()));
         verify(extensionClient, times(3)).fetch(eq(Setting.class), eq(settingName));
         verify(extensionClient, times(3)).list(eq(AnnotationSetting.class), any(), eq(null));
+        verify(templateEngineManager).clearCache(eq(metadata.getName()));
     }
 
     @Test
@@ -167,7 +174,8 @@ void reconcileDeleteRetryWhenThrowException() {
         when(themeRoot.get()).thenReturn(testWorkDir);
 
         final ThemeReconciler themeReconciler =
-            new ThemeReconciler(extensionClient, themeRoot, systemVersionSupplier);
+            new ThemeReconciler(extensionClient, themeRoot, systemVersionSupplier,
+                templateEngineManager);
 
         final int[] retryFlags = {0};
         when(extensionClient.fetch(eq(Setting.class), eq("theme-test-setting")))
@@ -196,7 +204,8 @@ void reconcileStatus() {
         when(themeRoot.get()).thenReturn(testWorkDir);
 
         final ThemeReconciler themeReconciler =
-            new ThemeReconciler(extensionClient, themeRoot, systemVersionSupplier);
+            new ThemeReconciler(extensionClient, themeRoot, systemVersionSupplier,
+                templateEngineManager);
         Theme theme = fakeTheme();
         theme.setStatus(null);
         theme.getSpec().setRequires(">2.3.0");