ios build: Take lines added by the flutter tool

Greg found that this is a side effect of the Flutter upgrade in
PR zulip#1426:

zulip#1444 (comment)
> And indeed, `git log -G flutter_lldbinit` in the Flutter tree
> finds this from earlier this month, 2025-03-06:
> flutter/flutter@eb07c5123

Committing it here, after building for iOS, which we forgot to do
when preparing that PR.

Author: chrisbobbe

ios/Runner.xcodeproj/xcshareddata/xcschemes/Runner.xcscheme

@@ -26,6 +26,7 @@
       buildConfiguration = "Debug"
       selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
       selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      customLLDBInitFile = "$(SRCROOT)/Flutter/ephemeral/flutter_lldbinit"
       shouldUseLaunchSchemeArgsEnv = "YES">
       <MacroExpansion>
          <BuildableReference
@@ -43,6 +44,7 @@
       buildConfiguration = "Debug"
       selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
       selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      customLLDBInitFile = "$(SRCROOT)/Flutter/ephemeral/flutter_lldbinit"
       launchStyle = "0"
       useCustomWorkingDirectory = "NO"
       ignoresPersistentStateOnLaunch = "NO"