Fix phpstan/phpstan#13960: Invalid closure.unusedUse error when including external files

[phpstan-bot]

Summary

When a closure contains require, include, require_once, or include_once, the included file inherits the variable scope of the closure. PHPStan was incorrectly reporting closure.unusedUse for variables passed via use() that could be accessed by the included file.

Changes

• Modified src/Rules/UnusedFunctionParametersCheck.php to treat Include_ nodes (which represent all four include/require variants) as using all defined variables, similar to how get_defined_vars() and func_get_args() are already handled.
• Removed two now-unnecessary baseline entries in phpstan-baseline.neon for src/Command/CommandHelper.php and src/Testing/PHPStanTestCase.php that were suppressing exactly this false positive.
• Added regression test in tests/PHPStan/Rules/Functions/data/bug-13960.php covering require, include, require_once, and include_once.
• Added test method testBug13960 in tests/PHPStan/Rules/Functions/UnusedClosureUsesRuleTest.php.

Root cause

The getUsedVariables() method in UnusedFunctionParametersCheck walks the AST to find variable references, but include/require statements don't directly reference variables — they just load a file. However, per PHP documentation, the included file inherits the variable scope of the line where the include occurs. The fix treats include/require the same as get_defined_vars(): all variables in scope are considered "used" since the included file could reference any of them.

Test

The regression test creates closures with use ($aap) containing each of the four include/require variants. Before the fix, all four produced false closure.unusedUse errors. After the fix, no errors are reported.

Fixes phpstan/phpstan#13960