Remove outdated Docker image section, add local cygdb instruction

[Sayeem3051]

This PR addresses issue #61511 by updating the debugging_extensions.rst documentation.

Summary of Changes

• Removed the outdated "Using Docker" section as the Docker image is out of date
• Added a new "Using cygdb for Cython debugging" section emphasizing local installations
• Documented that cygdb comes pre-installed with Cython
• Updated to reflect preference for local installations as discussed in the issue

As mentioned by @WillAyd in the issue discussion, the pandas team gets very little usage of the docker containers, so this change removes that documentation and focuses on the preferred local debugging approach using cygdb.

Closes

• Closes DOC: Docker image provided on "Debugging C extensions" is out of date #61511

Checklist

• This is a documentation-only change

• No tests needed (documentation change only)

• No type annotations needed (documentation change only)

• No whatsnew entry needed (documentation improvement)…nsDOC: Remove outdated Docker image from debugging_extensions documentationDOC: Remove outdated Docker image from debugging_extensions documentationUpdate debugging_extensions.rst

• Removed the 'Using Docker' section as the Docker image is out of date

• Added 'Using cygdb for Cython debugging' section emphasizing local installations

• Documented that cygdb comes pre-installed with Cython

• Updated to reflect preference for local installations as discussed in issue

Closes #61511

• closes #xxxx (Replace xxxx with the GitHub issue number)
• Tests added and passed if fixing a bug or adding a new feature
• All code checks passed.
• Added type annotations to new arguments/methods/functions.
• Added an entry in the latest doc/source/whatsnew/vX.X.X.rst file if fixing a bug or adding a new feature.

[WillAyd]

Ah cool - so cygdb works out of the box now? I vaguely recall it requiring a gcc and/or python built with particular flags, but if that is not necessary anymore that makes things much easier

[Sayeem3051]

Thanks for the question @WillAyd! Yes, cygdb does work out of the box now for most users. If you have Cython installed, cygdb is available without needing special build flags for Python or gcc.

There might be some edge cases where debug symbols or certain compiler options (like disabling optimization with -O0) could be needed, but for pandas development, cygdb typically just works as long as you've built pandas in debug mode as shown in the docs.

If any issues do arise, users can check for debug symbols and compiler flags, but the standard debug build should be sufficient for most debugging scenarios.

Thanks for your input on this! Let me know if you have any feedback or corrections.

[WillAyd]

Great thanks @Sayeem3051 !