Replace if-return with Assume API from Junit in DecimalParquetInputTest

[Codegass]

Fixes #12926.

Description

This PR improves the test cases in DecimalParquetInputTest by replacing the if-return blocks that check for unsupported parser types with assumeFalse-- Assume API from Junit.

Replaced if-return blocks with assumeFalse

The existing test cases used if-return blocks like this to skip tests for unsupported parser types:

// parquet-avro does not correctly convert decimal types
if (parserType.equals(ParquetExtensionsModule.PARQUET_AVRO_INPUT_PARSER_TYPE)) {  
  return;
}

This made the test logic implicit. It's preferable to make unsupported preconditions explicit using JUnit's assume methods. The assume function, introduced after JUnit 4, is designed to check for test pre-condition. As mentioned in the document:

Assume functions is a set of methods useful for stating assumptions about the conditions in which a test is meaningful. A failed assumption does not mean the code is broken, but that the test provides no useful information.

I replaced the if-return blocks with equivalent assumeFalse assertions:

// parquet-avro does not correctly convert decimal types
assumeFalse(parserType.equals(ParquetExtensionsModule.PARQUET_AVRO_INPUT_PARSER_TYPE));

A failed assumption will cause the test to be skipped, while still allowing the test to run for supported parser types. This makes the preconditions clearer without changing the test behavior.

This refactoring resolves the silent quit issue by using the Assume API to provide explicit output when tests are skipped.

I applied this change to all three test cases in DecimalParquetInputTest:

• testReadParquetDecimalFixedLen
• testReadParquetDecimali32
• testReadParquetDecimali64

This is a straightforward refactoring that improves test readability without altering functionality. No other code changes were made.

---

This PR has:

• been self-reviewed.
• added documentation for new or modified features or behaviors.
• a release note entry in the PR description.
• added Javadocs for most classes and all non-trivial methods. Linked related entities via Javadoc links.
• added or updated version, license, or notice information in licenses.yaml
• added comments explaining the "why" and the intent of the code wherever would not be obvious for an unfamiliar reader.
• added unit tests or modified existing tests to cover new code paths, ensuring the threshold for code coverage is met.
• added integration tests.
• been tested in a test Druid cluster.

[kfaraz]

Thanks for the changes, @Codegass . I have left some comments.

[kfaraz]

Druid code doesn't use the import static style.

Suggested change

	assumeFalse(parserType.equals(ParquetExtensionsModule.PARQUET_AVRO_INPUT_PARSER_TYPE));
	Assume.assumeFalse(parserType.equals(ParquetExtensionsModule.PARQUET_AVRO_INPUT_PARSER_TYPE));

[kfaraz]

These changes are not needed as this code is already formatted correctly according to the formatting style used by this project. Same comment for the other formatting changes.

[Codegass]

thank you for the suggestions! I just updated the pr based on them.

[kfaraz]

Thanks a lot for your first contribution to Druid, @Codegass !