ci: build and run test suite in CI

Since our merge queue is finally working reliably [0], we should run
the whole test suite as part of this repository. As long as we do not
have a Nix binary cache, this is much slower than it should/could be,
unfortunately. We again introduced a bug that we would have caught
with these checks running in GitHubs (slow) CI [1].

[0] cyberus-technology#93
[1] cyberus-technology#89

Signed-off-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>
On-behalf-of: SAP philipp.schuster@sap.com

Author: phip1611

.github/workflows/build.yml

@@ -11,7 +11,7 @@ concurrency:
   cancel-in-progress: ${{ github.event_name == 'pull_request' }}
 
 jobs:
-  checks:
+  build:
     name: Checks, Build, Lints
     runs-on: ubuntu-latest
     steps:
@@ -20,7 +20,7 @@ jobs:
       # We restore Nix evaluation and Nix tarball cache, speeding up the CI.
       # This does not cover any Nix artifacts from the Nix store.
       - name: Restore Nix cache
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: ~/.cache/nix
           key: nix-cache-${{ github.job }}
@@ -46,10 +46,14 @@ jobs:
         run: |
           nix build -L .#checks.x86_64-linux.all
           # Run all other flake-wide checks
-          # TODO add once we have quicker CI runners
-          # This
-          # nix flake check
+          nix flake check
       - name: Eval Default Test Suite
         run: nix eval -L .#tests.x86_64-linux.default.driver
       - name: Eval Long-Running Test Suite
         run: nix eval -L .#tests.x86_64-linux.long_migration_with_load.driver
+      - name: Build Default Test Suite
+        run: nix build -L .#tests.x86_64-linux.default.driver
+      - name: Build Long-Running Test Suite
+        run: nix build -L .#tests.x86_64-linux.long_migration_with_load.driver
+      - name: Run Default Test Suite
+        run: nix run -L .#tests.x86_64-linux.default.driver