[GitHub] Add permissions for CI build handling

[hugtalbot]

Increase permissions for token to allow Python scripts write in PR and create statuses

Linked (but no dependency) with : sofa-framework/ci#86

[ci-depends-on https://github.com/sofa-framework/ci/pull/86]

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By submitting this pull request, I acknowledge that
I have read, understand, and agree SOFA Developer Certificate of Origin (DCO).

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Reviewers will merge this pull-request only if

• it builds with SUCCESS for all platforms on the CI.
• it does not generate new warnings.
• it does not generate new unit test failures.
• it does not generate new scene test failures.
• it does not break API compatibility.
• it is more than 1 week old (or has fast-merge label).

[github-actions]

[ci-depends-on] detected.

To unlock the merge button, you must

• Merge or close Refactor PR data fetching and function parameters ci#86
  For this build, the following CMake flags will be set
  -DCI_GIT_REPOSITORY='https://github.com/sofa-framework/ci'
  -DCI_GIT_TAG='hugtalbot-patch-2'