Only run ubuntu in OS matrix. Speeds verifying debian package creation

.github/workflows/release.yml

@@ -17,7 +17,7 @@ jobs:
   publish:
     strategy:
       matrix:
-        os: [macos-latest, ubuntu-latest, windows-latest]
+        os: [ubuntu-latest]
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v3
@@ -67,7 +67,7 @@ jobs:
         run: |
           # Install Debian Packager
           sudo apt install ruby
-          get install fpm --user-install
+          gem install fpm --user-install
 
           # Copy app files into expected output directory structure
           mkdir -p package/opt package/usr/share/applications package/usr/share/icons/hicolor/128x128/apps