Backport workflow-hardening fix (excessive-permissions) to `v4.1.0`

[CharlieMCY]

Summary

The default branch already hardened .github/workflows/installer.yml against the issue(s) below, but the release branch v4.1.0 still carries it. This proposes the same, minimal fix for that branch.

Affected branch / file

• branch: v4.1.0 (HEAD 325181d4)
• file: .github/workflows/installer.yml

What's flagged (by zizmor)

• excessive-permissions — workflow/job granted broader permissions than needed

These are already resolved on the default branch in f4569f0 but the fix was not backported to v4.1.0.

Suggested fix

Concretely:

• • permissions.contents = 'read'

--- a/.github/workflows/installer.yml
+++ b/.github/workflows/installer.yml
@@ -64,3 +64,5 @@
 
       - name: Test code-server
         run: yarn test:standalone-release code-server
+permissions:
+  contents: read

(Whitespace is normalized in the diff above; only the security-relevant lines change.) This patch was checked locally with zizmor and actionlint: the flagged finding(s) are cleared on the affected construct and no new lint or security findings are introduced.

---

This issue was prepared by an automated workflow-hardening analysis and double-checked against the two scanners above. Please review before merging — happy to send a pull request instead if that's preferred.

[linear-code]

DEVEX-502