fix(ci): move actions from snapcore to canonical (#1916)

The `snapcore/action-publish` action no longer has tags, so we need to
switch it over. Might as well do the build one too.

.github/workflows/tests.yaml

@@ -127,7 +127,7 @@ jobs:
         with:
           fetch-depth: 0
       - name: Build snap
-        uses: snapcore/action-build@v1
+        uses: canonical/action-build@v1
         id: snapcraft
       - name: Upload snap artifact
         uses: actions/upload-artifact@v4
@@ -152,7 +152,7 @@ jobs:
           fi
       - name: Publish feature branch to edge/${{ steps.vars.outputs.branch }}
         if: ${{ env.SNAPCRAFT_STORE_CREDENTIALS != '' }}
-        uses: snapcore/action-publish@v1
+        uses: canonical/action-publish@v1
         env:
           SNAPCRAFT_STORE_CREDENTIALS: ${{ secrets.SNAPCRAFT_STORE_CREDENTIALS }}
         with: