duplicate the snap github action to publish new humble track

.github/workflows/snap.yaml

@@ -47,3 +47,40 @@ jobs:
       with:
         snap: ${{needs.build.outputs.snap-file}}
         release: ${{ startsWith(github.ref, 'refs/tags/') && 'candidate' || 'edge'}}
+
+  build22:
+    runs-on: ubuntu-latest
+    outputs:
+      snap-file: ${{ steps.build-snap22.outputs.snap }}
+    steps:
+    - uses: actions/checkout@v2
+      with:
+        # full history for latest tag name
+        fetch-depth: 0
+    - uses: snapcore/action-build@v1
+      id: build-snap22
+
+    # Make sure the snap is installable
+    - run: |
+        sudo snap install --dangerous ${{ steps.build-snap22.outputs.snap }}
+
+    - uses: actions/upload-artifact@v3
+      with:
+        name: plotjuggler-snap22
+        path: ${{ steps.build-snap22.outputs.snap }}
+
+  publish22:
+    if: github.ref == 'refs/heads/main' || startsWith(github.ref, 'refs/tags/')
+    runs-on: ubuntu-latest
+    needs: build22
+    steps:
+    - uses: actions/download-artifact@v3
+      with:
+        name: plotjuggler-snap22
+        path: .
+    - uses: snapcore/action-publish@v1
+      env:
+        SNAPCRAFT_STORE_CREDENTIALS: ${{ secrets.STORE_LOGIN }}
+      with:
+        snap: ${{needs.build.outputs.snap-file}}
+        release: humble/${{ startsWith(github.ref, 'refs/tags/') && 'candidate' || 'edge'}}