test: Enable test for consistent-return rule (#159)

## Summary
- Uncommented the `consistent-return.test.ts` test file in
`rstest.config.mts` (line 41)
- This enables testing for the `consistent-return` rule implementation

## Context
The `consistent-return` rule ensures that functions always return a
value or never return a value consistently. This test was previously
commented out and is now being enabled.

## Testing
The CI will run the tests to verify the implementation passes all test
cases. If tests fail, the rule implementation may need to be fixed or
implemented from scratch.

## References
- TypeScript-ESLint consistent-return rule:
https://typescript-eslint.io/rules/consistent-return/
- Original ESLint consistent-return:
https://eslint.org/docs/latest/rules/consistent-return

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Co-authored-by: claude[bot] <41898282+claude[bot]@users.noreply.github.com>
Co-authored-by: Claude <noreply@anthropic.com>

Author: 3 people

packages/rslint-test-tools/rstest.config.mts

@@ -38,7 +38,7 @@ export default defineConfig({
     './tests/typescript-eslint/rules/class-methods-use-this/class-methods-use-this.test.ts',
     './tests/typescript-eslint/rules/consistent-generic-constructors.test.ts',
     './tests/typescript-eslint/rules/consistent-indexed-object-style.test.ts',
-    // './tests/typescript-eslint/rules/consistent-return.test.ts',
+    './tests/typescript-eslint/rules/consistent-return.test.ts',
     // './tests/typescript-eslint/rules/consistent-type-assertions.test.ts',
     // './tests/typescript-eslint/rules/consistent-type-definitions.test.ts',
     './tests/typescript-eslint/rules/consistent-type-exports.test.ts',