Fix cache warmer: run real test to resolve surefire provider (#1385)

## Summary
The cache warmer was not caching `surefire-junit-platform:3.1.2` because
surefire resolves its provider JAR lazily at test execution time, not at
plugin initialization. The previous approach (`-Dtest=NoSuchTest`)
failed before surefire downloaded the provider.

Fix: run a real lightweight test
(`DatabricksParameterMetaDataTest#testInitialization`) to force full
surefire provider resolution.

### Verified locally
All 4 previously missing artifacts are now in the local cache after
running the test:
- `surefire-junit-platform:3.1.2` (blocked unit-tests + integration
tests)
- `maven-toolchains-plugin:3.2.0` (blocked unit-tests)
- `maven-clean-plugin:3.2.0` (blocked coverage)
- `exec-maven-plugin:1.2.1` (blocked coverage)

The 5 maven-metadata.xml warnings are non-blocking (Maven falls back to
cached plugin JARs).

## Test plan
- [x] Verified locally: `mvn -pl jdbc-core test
-Dtest="DatabricksParameterMetaDataTest#testInitialization"` passes and
resolves all missing plugins
- [ ] After merge: re-trigger cache warmer on main, then re-run PR #1371
CI

NO_CHANGELOG=true

This pull request was AI-assisted by Isaac.

---------

Signed-off-by: Gopal Lal <gopal.lal@databricks.com>
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: gopalldb

.github/workflows/warmMavenCache.yml

@@ -142,14 +142,18 @@ jobs:
           # build-time plugins (spotless, toolchains, owasp) that mvn install alone
           # doesn't trigger.
 
-          echo "=== Step 2: Running unit test compilation + surefire resolution ==="
-          mvn -B -pl jdbc-core test -Dtest=NoSuchTest -DfailIfNoTests=false -Ddependency-check.skip=true || true
+          # Step 2: Run a real unit test to trigger full surefire provider resolution.
+          # surefire-junit-platform is resolved lazily at test execution time, not at
+          # plugin initialization. We need at least one test to actually run.
+          echo "=== Step 2: Running a single unit test to resolve surefire provider ==="
+          mvn -B -pl jdbc-core test -Dtest="DatabricksParameterMetaDataTest#testInitialization" -Ddependency-check.skip=true || true
 
           echo "=== Step 3: Running spotless check ==="
           mvn -B --errors spotless:check || true
 
+          # Step 4: Run jacoco with a real test to resolve jacoco agent + report plugins
           echo "=== Step 4: Running jacoco coverage ==="
-          mvn -B -pl jdbc-core test -Dtest=NoSuchTest -DfailIfNoTests=false jacoco:report -Ddependency-check.skip=true || true
+          mvn -B -pl jdbc-core test -Dtest="DatabricksParameterMetaDataTest#testInitialization" jacoco:report -Ddependency-check.skip=true || true
 
           echo "=== Step 5: Running integration test compilation ==="
           mvn -B -pl jdbc-core compile test-compile -Ddependency-check.skip=true || true