chore(deps): update determinatesystems/update-flake-lock action to v28

Author: renovate[bot]

.github/workflows/update-flake.yml

@@ -16,7 +16,7 @@ jobs:
         uses: ./.github/actions/setup-tests
 
       - name: Update flake.lock
-        uses: DeterminateSystems/update-flake-lock@da2fd6f2563fe3e4f2af8be73b864088564e263d # v20
+        uses: DeterminateSystems/update-flake-lock@834c491b2ece4de0bbd00d85214bb5e83b4da5c6 # v28
         id: update-flake
         with:
           pr-title: "chore(deps): Update flake.lock"