Java: add test exercising Gradle download pruning

[smowton]

This exhibits that buildless doesn't attempt to download junit-bom, a non-jar dependency of junit-jupiter-api.

[Copilot]

Pull Request Overview

This PR introduces a new integration test and corresponding change note to ensure that, under buildless mode with Gradle, the system no longer attempts to download non-jar Maven artifacts (e.g. BOMs).

• Updates the change notes to document the fix.
• Adds a Python integration test to exercise Gradle download pruning.
• Introduces a Java test file that, however, appears to misuse the @test annotation.

Reviewed Changes

Copilot reviewed 3 out of 8 changed files in this pull request and generated 1 comment.

File	Description
java/ql/lib/change-notes/2025-03-27-gradle-fetch-reduction.md	Updated changenotes explaining the download pruning fix.
java/ql/integration-tests/java/buildless-gradle-boms/test.py	Added a new integration test for Gradle BOM download pruning.
java/ql/integration-tests/java/buildless-gradle-boms/src/main/java/com/fractestexample/Test.java	Contains a method that improperly uses the JUnit @test annotation as a parameter.

Files not reviewed (5)

• java/ql/integration-tests/java/buildless-gradle-boms/build.gradle: Language not supported
• java/ql/integration-tests/java/buildless-gradle-boms/buildless-fetches.expected: Language not supported
• java/ql/integration-tests/java/buildless-gradle-boms/diagnostics.expected: Language not supported
• java/ql/integration-tests/java/buildless-gradle-boms/settings.gradle: Language not supported
• java/ql/integration-tests/java/buildless-gradle-boms/source_archive.expected: Language not supported

Comments suppressed due to low confidence (1)

java/ql/integration-tests/java/buildless-gradle-boms/test.py:1

• The integration test currently creates a database but does not verify that the BOM artifact is pruned. Consider adding assertions or checks to confirm that no unwanted downloads occur.

def test(codeql, java, gradle_8_3):

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[Copilot]

Using org.junit.jupiter.api.Test as a parameter type appears to be incorrect; consider annotating the method with @test and removing the parameter to correctly define a test method.

Suggested change

	public Fraction test(org.junit.jupiter.api.Test t) { return Fraction.ONE; }
	@Test
	public Fraction test() { return Fraction.ONE; }