minor #17246 GitHub Workflows security hardening (sashashura)

This PR was submitted for the 6.2 branch but it was merged into the 4.4 branch instead.

Discussion
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GitHub Workflows security hardening

This PR adds explicit [permissions section](https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#permissions) to workflows. This is a security best practice because by default workflows run with [extended set of permissions](https://docs.github.com/en/actions/security-guides/automatic-token-authentication#permissions-for-the-github_token) (except from `on: pull_request` [from external forks](https://securitylab.github.com/research/github-actions-preventing-pwn-requests/)). By specifying any permission explicitly all others are set to none. By using the principle of least privilege the damage a compromised workflow can do (because of an [injection](https://securitylab.github.com/research/github-actions-untrusted-input/) or compromised third party tool or action) is restricted.
It is recommended to have [most strict permissions on the top level](https://github.com/ossf/scorecard/blob/main/docs/checks.md#token-permissions) and grant write permissions on [job level](https://docs.github.com/en/actions/using-jobs/assigning-permissions-to-jobs) case by case.

Commits
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c62747f Update ci.yaml

Author: OskarStark

.github/workflows/ci.yaml

@@ -8,6 +8,9 @@ on:
         branches-ignore:
             - 'github-comments'
 
+permissions:
+    contents: read
+
 jobs:
     symfony-docs-builder-build:
         name: Build (symfony-tools/docs-builder)