fix obsolete runs-on in workflow

.github/workflows/ci.yml

@@ -29,7 +29,7 @@ jobs:
           # `git describe` output gets baked into the binary for `moonfire-nvr --version`.
           # Fetch all revs so it can see tag history.
           fetch-depth: 0
-          filter: 'tree:0'
+          filter: "tree:0"
       - name: Cache
         uses: actions/cache@v4
         with:
@@ -79,7 +79,7 @@ jobs:
       - run: cd ui && pnpm run check-format
   license:
     name: Check copyright/license headers
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     steps:
       - name: Checkout
         uses: actions/checkout@v4