Restrict permissions in GHA workflows

[JeanChristopheMorinPerso]

Restrict permissions in GHA workflows to fix scorecard warnings like this one: https://github.com/AcademySoftwareFoundation/rez/security/code-scanning/33.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 58.39%. Comparing base (980dd0b) to head (6bcae92).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #1782 +/- ## ======================================= Coverage 58.39% 58.39% ======================================= Files 126 126 Lines 17205 17205 Branches 3519 3519 ======================================= Hits 10047 10047 Misses 6491 6491 Partials 667 667 ```

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