PPA: Build for Ubuntu Impish

.github/workflows/package.yml

@@ -7,7 +7,11 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        distro: [ubuntu-hirsute, ubuntu-groovy, ubuntu-focal]
+        distro:
+          - ubuntu-impish
+          - ubuntu-hirsute
+          - ubuntu-groovy
+          - ubuntu-focal
     steps:
       - uses: actions/checkout@v2
 
@@ -30,6 +34,14 @@ jobs:
           email: release+launchpad@kiwix.org
           distro: ${{ matrix.distro }}
 
+      - uses: legoktm/gh-action-build-deb@ubuntu-impish
+        if: matrix.distro == 'ubuntu-impish'
+        name: Build package for ubuntu-impish
+        id: build-ubuntu-impish
+        with:
+          args: --no-sign
+          ppa: ${{ steps.ppa.outputs.ppa }}
+
       - uses: legoktm/gh-action-build-deb@ubuntu-hirsute
         if: matrix.distro == 'ubuntu-hirsute'
         name: Build package for ubuntu-hirsute