ci(build): pass signing credentials to Gradle build step

Env vars were missing from the build step, causing release
signing to fall through to empty defaults.

Author: Enginex0

.github/workflows/build.yml

@@ -74,6 +74,9 @@ jobs:
           fi
         env:
           PROFILE: ${{ matrix.profile }}
+          KEYSTORE_PASSWORD: ${{ secrets.KEYSTORE_PASSWORD }}
+          KEY_ALIAS: ${{ secrets.KEY_ALIAS }}
+          KEY_PASSWORD: ${{ secrets.KEY_PASSWORD }}
 
       - uses: actions/upload-artifact@v4
         with: