ci: assert that we sample certain transitions (#6339)

It happened in the past that we screwed up the `preconditions` of the
state machine test such that no more transitions were sampled that
actually send packets. To protect against this, we use the newly
introduced logs and grep for certain transitions.

In the future, we can consider emitting a more structured output, like
writing all testcases to a DB and run more complex queries against it to
ensure that certain cases are covered.

.github/workflows/_rust.yml

@@ -88,6 +88,9 @@ jobs:
       - uses: ./.github/actions/setup-rust
         id: setup-rust
       - uses: ./.github/actions/setup-tauri
+      - uses: taiki-e/install-action@v2
+        with:
+          tool: ripgrep
       - name: "cargo test"
         shell: bash
         run: |
@@ -95,6 +98,11 @@ jobs:
           # First, run all tests.
           cargo test --all-features ${{ steps.setup-rust.outputs.packages }} -- --include-ignored --nocapture
 
+          # Assert that we sample certain transitions
+          rg SendICMPPacketToCidrResource $TESTCASES_DIR
+          rg SendICMPPacketToDnsResource $TESTCASES_DIR
+          rg SendDnsQueries $TESTCASES_DIR
+
           # Backup dumped state and transition samples
           mv $TESTCASES_DIR $TESTCASES_BACKUP_DIR