Give python package hints to use our ncurses library

What does this MR do?

This MR supports the building of python 3.13 .

Python's configure script will try to use pkg-config to infer cflags and lflags for ncurses ; because of this we can end up using the system-installed ncurses headers with our (possibly incompatible) version of ncurses. This can lead to build time but also runtime errors.

Specifying the environment variables from this MR pre-empts the situation described above.

Based on reviewer feedback I am reworking the ncurses install to produce pkg-config files and make sure python's configure runs with a properly set PKG_CONFIG_PATH.

Give python package hints to use our ncurses library

Part of fix for #9394 Related: !8786

Related issues

#9394

Checklist

See Definition of done.

For anything in this list which will not be completed, please provide a reason in the MR discussion.

Required

• MR title and description are up to date, accurate, and descriptive.
• MR targeting the appropriate branch.
• Latest Merge Result pipeline is green.
• When ready for review, MR is labeled workflowready for review per the Distribution MR workflow.

For GitLab team members

If you don't have access to this, the reviewer should trigger these jobs for you during the review process.

• The manual Trigger:ee-package jobs have a green pipeline running against latest commit.
• If config/software or config/patches directories are changed, make sure the build-package-on-all-os job within the Trigger:ee-package downstream pipeline succeeded.
• If you are changing anything SSL related, then the Trigger:package:fips manual job within the Trigger:ee-package downstream pipeline must succeed.
• If CI configuration is changed, the branch must be pushed to dev.gitlab.org to confirm regular branch builds aren't broken.

Expected (please provide an explanation if not completing)

• Test plan indicating conditions for success has been posted and passes.
• Documentation created/updated.
• Tests added.
• Integration tests added to GitLab QA.
• Equivalent MR/issue for the GitLab Chart opened.
• Validate potential values for new configuration settings. Formats such as integer 10, duration 10s, URI scheme://user:passwd@host:port may require quotation or other special handling when rendered in a template and written to a configuration file.