Add xpkg.upbound.io login step to workflow

Adds a login step to publish artifacts workflow for xpkg.upbound.io.

Signed-off-by: hasheddan <georgedanielmangum@gmail.com>

.github/workflows/ci.yml

@@ -18,6 +18,7 @@ env:
   # a step 'if env.AWS_USR' != ""', so we copy these to succinctly test whether
   # credentials have been provided before trying to run steps that need them.
   DOCKER_USR: ${{ secrets.DOCKER_USR }}
+  XPKG_ACCESS_ID: ${{ secrets.XPKG_ACCESS_ID }}
   AWS_USR: ${{ secrets.AWS_USR }}
 
 jobs:
@@ -302,7 +303,15 @@ jobs:
         with:
           username: ${{ secrets.DOCKER_USR }}
           password: ${{ secrets.DOCKER_PSW }}
-
+
+      - name: Login to Upbound
+        uses: docker/#-action@v1
+        if: env.XPKG_ACCESS_ID != ''
+        with:
+          registry: xpkg.upbound.io
+          username: ${{ secrets.XPKG_ACCESS_ID }}
+          password: ${{ secrets.XPKG_TOKEN }}     
+
       - name: Publish Artifacts to S3 and Docker Hub
         run: make -j2 publish BRANCH_NAME=${GITHUB_REF##*/}
         if: env.AWS_USR != '' && env.DOCKER_USR != ''
@@ -319,4 +328,4 @@ jobs:
           CHANNEL: master
           AWS_ACCESS_KEY_ID: ${{ secrets.AWS_USR }}
           AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_PSW }}
-
+