gh-37883: Safely skip test_resource file size tests when limits are strict

[Shrey-N]

This fixes the Standing issue #37883 where test_resource would fail on systems with file size limitations

Previous attempts (like #140872) tried to introduce massive refactoring and helper classes. Based on reviewer feedback I read there, I have tried a minimal fix

• It checks if the system's hard limit is large enough, and if the OS actually allows the limit to be modified. If not, it uses self.skipTest with an informative message rather than failing with an unhandled OSError or ValueError.
• It replaces the fragile dual try...finally resource restoration blocks with self.addCleanup(), guaranteeing that limits are reset even during a test assertion failure.

Fixes #37883

• Issue: test_resource fails when file size is limited #37883

[python-cla-bot]

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[Shrey-N]

I have added a news entry, though I am not sure if it's necessary or for this fix, Please let me know if I should remove it :)

[encukou]

This looks good!

We don't need a NEWS entry for a test-only change.

[Shrey-N]

@encukou Alrighty thank you, I was confused as to add it or not so thank you for clearing that up :), also I will incorporate your reviews in a second :)