CI: try to use actions-metadata rather than local script

.github/actions/notify-push/action.yml

@@ -0,0 +1,20 @@
+name: 'Notify on Push'
+description: 'Notify Matrix room'
+
+inputs:
+  room:
+    description: 'Matrix Room ID'
+    required: true
+  token:
+    description: 'Matrix Token'
+    required: true
+  message:
+    description: 'Message to send'
+    required: true
+
+runs:
+  using: "composite"
+  steps:
+    - shell: bash
+      run: |
+        curl -s -XPOST -d $( echo "$INPUT_MESSAGE" | jq -Rs '{"msgtype": "m.text", "body":@text}' ) "https://matrix.org/_matrix/client/r0/rooms/%21${INPUT_ROOM}/send/m.room.message?access_token=${INPUT_TOKEN}" > /dev/null

.github/workflows/push.yml

@@ -79,19 +79,20 @@ jobs:
         run: make install VERBOSE=1
       - name: "notify: ok"
         if: ${{ success() && github.repository == 'calamares/calamares' }}
-        env:
-          MATRIX_TOKEN: ${{ secrets.MATRIX_TOKEN }}
-          MATRIX_ROOM: ${{ secrets.MATRIX_ROOM }}
-        run: |
-          "$SRCDIR/ci/notify.sh" OK '${{ github.workflow }}' '${{ github.repository }}' '${{ github.actor }}' '${{ github.event.ref }}' \
-            '${{ steps.pre_build.outputs.message }}' \
-            ''
+        uses: ./.github/actions/notify-push
+        with:
+          TOKEN: ${{ secrets.MATRIX_TOKEN }}
+          ROOM: ${{ secrets.MATRIX_ROOM }}
+          MESSAGE: |
+            OK ${{ github.workflow }} in ${{ github.repository }} by ${{ github.actor }} on ${{ github.event.ref }}
+            .. ${{ steps.pre_build.outputs.message }}
       - name: "notify: fail"
         if: ${{ failure() && github.repository == 'calamares/calamares' }}
-        env:
-          MATRIX_TOKEN: ${{ secrets.MATRIX_TOKEN }}
-          MATRIX_ROOM: ${{ secrets.MATRIX_ROOM }}
-        run: |
-          "$SRCDIR/ci/notify.sh" FAIL '${{ github.workflow }}' '${{ github.repository }}' '${{ github.actor }}' '${{ github.event.ref }}' \
-            '${{ steps.pre_build.outputs.message }}' \
-            '${{ github.event.compare }}'
+        uses: ./.github/actions/notify-push
+        with:
+          TOKEN: ${{ secrets.MATRIX_TOKEN }}
+          ROOM: ${{ secrets.MATRIX_ROOM }}
+          MESSAGE: |
+            FAIL ${{ github.workflow }} in ${{ github.repository }} by ${{ github.actor }} on ${{ github.event.ref }}
+              .. ${{ steps.pre_build.outputs.message }}
+              .. ${{ github.event.compare }}