Update the GitHub action runner to ubuntu-latest

Author: craigthomas

.github/workflows/gradle.yml

@@ -2,7 +2,7 @@ name: Build Test Coverage
 on: [push, pull_request]
 jobs:
   run:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     steps:
     - name: Checkout
       uses: actions/checkout@v3
@@ -18,4 +18,4 @@ jobs:
     - name: Codecov
       uses: codecov/codecov-action@v4.2.0
       env:
-          CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}
+        CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}