[timtebeek]

UseWiremockExtension swapped org.junit.Rule for RegisterExtension across the whole file once it saw a new WireMockRule(..), so other rules in the same class were retyped too:

@Rule public WireMockRule wm = new WireMockRule(7001);
@Rule public TemporaryFolder tmp = new TemporaryFolder();

came out as @RegisterExtension public TemporaryFolder tmp, which Jupiter rejects at runtime. Within JUnit4to5Migration the recipe runs before TemporaryFolderToTempDir and TestRuleToTestInfo, so those then no longer recognised their fields. Now only the @Rule on a WireMockRule field becomes @RegisterExtension, and org.junit.Rule is only removed when nothing else uses it. Through JUnit4to5Migration, the folder now becomes @TempDir public File tmp.

This overlaps with #1191, which adds a second file-wide ChangeType in the same spot, for org.junit.ClassRule. That would hit the same problem for other class rules (e.g. a @ClassRule static TemporaryFolder). Once this is merged, #1191 could match @org.junit.ClassRule in the new visitVariableDeclarations alongside @Rule instead of queueing a ChangeType. Its classRuleBecomesStaticRegisteredExtension test should pass unchanged.

Fixes item B1 of #1211.