trivial: use github actions to build snaps

.github/workflows/main.yml

@@ -74,6 +74,13 @@ jobs:
           echo $GITHUB_WORKSPACE
           docker run --privileged -e CI=true -t -v $GITHUB_WORKSPACE:/github/workspace docker.pkg.github.com/fwupd/fwupd/fwupd-${{matrix.os}}:latest
 
+  snap:
+    uses: ./.github/workflows/snap.yml
+    with:
+      deploy:  ${{ github.event_name }} == "push'
+      channel: edge
+    secrets: inherit
+
   macos:
     runs-on: macos-12
     steps:

.github/workflows/snap-stable.yml

@@ -0,0 +1,13 @@
+name: Publish to snap stable channel
+
+on:
+  release:
+    types: [published]
+
+jobs:
+  snap:
+    uses: ./.github/workflows/snap.yml
+    with:
+      deploy:  true
+      channel: stable
+    secrets: inherit

.github/workflows/snap.yml

@@ -0,0 +1,38 @@
+name: Snap workflow
+on:
+  workflow_call:
+    inputs:
+      channel:
+        required: true
+        type: string
+      deploy:
+        required: true
+        type: boolean
+
+jobs:
+  build-snap:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v3
+    - uses: snapcore/action-build@v1
+      id: snapcraft
+    - uses: actions/upload-artifact@v3
+      with:
+        name: snap
+        path: ${{ steps.snapcraft.outputs.snap }}
+
+  deploy-store:
+    needs: build-snap
+    runs-on: ubuntu-latest
+    if: ${{ inputs.perform_deploy }}
+    steps:
+    - uses: actions/checkout@v2
+    - uses: actions/download-artifact@v3
+      with:
+        name: snap
+    - uses: snapcore/action-publish@v1
+      env:
+        SNAPCRAFT_STORE_CREDENTIALS: ${{ secrets.STORE_LOGIN }}
+      with:
+        snap: ${{ steps.build.outputs.snap }}
+        release: ${{ inputs.channel }}