generate_test_cert_macros.py: Removed absolute path from the rendered output

[minosgalanakis]

Description

As part of the post release activities, fixing minor inconveniences of the tooling required to build a release.

This pr adjust the generate_test_cert_macros.py logic to use relative paths BEFORE rendering the templates for the auto-generated files but continue using absolute paths internally so it can be called from different locations in the tree.

Needs to be tested locally with ./framework/scripts/generate_test_cert_macros.py and inspection of the header files.

PR checklist

Please add the numbers (or links) of the associated pull requests for consuming branches. You can omit branches where this pull request is not needed.

• TF-PSA-Crypto development PR not required because: script contained here
• TF-PSA-Crypto 1.1 PR not required because: script contained here
• mbedtls development PR not required because: script contained here
• mbedtls 4.1 PR not required because: script contained here
• mbedtls 3.6 PR not required because: script contained here

[bjwtaylor]

The changes look good but there is a ci failure that will need to be resolved.

[ronald-cron-arm]

Why do you mention make_generated_files.py here where it is about scripts/generate_test_cert_macros.py?

[ronald-cron-arm]

Otherwise could you clean-up the PR description? Remove the "Notes for the submitter", update the PR checklist.

[minosgalanakis]

Why do you mention make_generated_files.py here where it is about scripts/generate_test_cert_macros.py?

Because generate_test_cert_macros is called by make_generated_files, but yes you are right it could be more specific.

Also the CI failure is the typical intermitten ssl one, restarted

[ronald-cron-arm]

Why do you mention make_generated_files.py here where it is about scripts/generate_test_cert_macros.py?

Because generate_test_cert_macros is called by make_generated_files, but yes you are right it could be more specific.

Please update the title and PR description accordingly.

[ronald-cron-arm]

See #313 (comment)

[gilles-peskine-arm]

There is already a fix for that in #231. Let's not spend more time making a second one.