test(spanner): apply withoutAnnotations to all GAX mocks for Java 8 compatibility

[lqiu96]

Apply Mockito's withSettings().withoutAnnotations() to all mocks of GAX interfaces and classes across google-cloud-spanner tests to prevent Java 8 ArrayStoreException during reflection over JSpecify type-use annotations.

[gemini-code-assist]

Code Review

This pull request updates several test files to mock classes using withSettings().withoutAnnotations() to prevent ArrayStoreException issues on Java 8 caused by JSpecify type-use annotations. The review feedback points out that child3 of type OpenTelemetryApiTracer in CompositeTracerTest.java is still annotated with @Mock, which will likely trigger the same Java 8 compatibility issue, and suggests mocking it manually with disabled annotations as well.

[gemini-code-assist]

The child3 field of type OpenTelemetryApiTracer is still annotated with @Mock. Since OpenTelemetryApiTracer implements ApiTracer (a GAX interface), mocking it without disabling annotations will trigger the same ArrayStoreException on Java 8 due to JSpecify type-use annotations. To ensure full Java 8 compatibility, child3 should also be mocked manually using withSettings().withoutAnnotations().

  private ApiTracer child1;
  private ApiTracer child2;
  private OpenTelemetryApiTracer child3;
  private MetricsTracer child4;

  private CompositeTracer compositeTracer;

  @Before
  public void setup() {
    child1 = mock(ApiTracer.class, withSettings().withoutAnnotations());
    child2 = mock(ApiTracer.class, withSettings().withoutAnnotations());
    child3 = mock(OpenTelemetryApiTracer.class, withSettings().withoutAnnotations());
    child4 = mock(MetricsTracer.class, withSettings().withoutAnnotations());
    compositeTracer = new CompositeTracer(ImmutableList.of(child1, child2, child3, child4));