CI: Remove some of the Matrix notification scripts

The GitHub Matrix-integration widget does these notifications,
more efficiently than running curl by hand.

.github/workflows/issues.yml

@@ -8,20 +8,6 @@ jobs:
   notify:
     runs-on: ubuntu-latest
     steps:
-      - name: "notify: new"
-        if: github.event.issue.state == 'open'
-        uses: calamares/actions/matrix-notify@v4
-        with:
-          token: ${{ secrets.MATRIX_TOKEN }}
-          room: ${{ secrets.MATRIX_ROOM }}
-          message: "OPENED ${{ github.event.issue.html_url }} by ${{ github.actor }} ${{ github.event.issue.title }}"
-      - name: "notify: closed"
-        if: github.event.issue.state != 'open'
-        uses: calamares/actions/matrix-notify@v4
-        with:
-          token: ${{ secrets.MATRIX_TOKEN }}
-          room: ${{ secrets.MATRIX_ROOM }}
-          message: "CLOSED ${{ github.event.issue.html_url }} by ${{ github.actor }} ${{ github.event.issue.title }}"
       - name: "remove in-progress label"
         if: github.event.issue.state != 'open'
         run: |

.github/workflows/nightly-debian.yml

@@ -68,19 +68,3 @@ jobs:
       - name: "build"
         id: build
         uses: calamares/actions/generic-build@v4
-      - name: "notify: ok"
-        if: ${{ success() && github.repository == 'calamares/calamares' }}
-        uses: calamares/actions/matrix-notify@v4
-        with:
-          token: ${{ secrets.MATRIX_TOKEN }}
-          room: ${{ secrets.MATRIX_ROOM }}
-          message: |
-            OK ${{ github.workflow }} in ${{ github.repository }} ${{ steps.build.outputs.git-summary }}
-      - name: "notify: fail"
-        if: ${{ failure() && github.repository == 'calamares/calamares' }}
-        uses: calamares/actions/matrix-notify@v4
-        with:
-          token: ${{ secrets.MATRIX_TOKEN }}
-          room: ${{ secrets.MATRIX_ROOM }}
-          message: |
-            FAIL ${{ github.workflow }} in ${{ github.repository }} ${{ steps.build.outputs.git-summary }}