GH Actions: do not persist credentials

> By default, using `actions/checkout` causes a credential to be persisted in the checked-out repo's `.git/config`, so that subsequent `git` operations can be authenticated.
>
> Subsequent steps may accidentally publicly persist `.git/config`, e.g. by including it in a publicly accessible artifact via `actions/upload-artifact`.
>
> However, even without this, persisting the credential in the `.git/config` is non-ideal unless actually needed.
>
> **Remediation**
>
> Unless needed for `git` operations, `actions/checkout` should be used with `persist-credentials: false`.
>
> If the persisted credential is needed, it should be made explicit with `persist-credentials: true`.

This has now been addressed in all workflows.

Refs:
* https://unit42.paloaltonetworks.com/github-repo-artifacts-leak-tokens/
* https://docs.zizmor.sh/audits/#artipacked

Author: jrfnl

.github/workflows/cs.yml

@@ -22,6 +22,8 @@ jobs:
     steps:
       - name: Checkout code
         uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5.0.1
+        with:
+          persist-credentials: false
 
       - name: Install PHP
         uses: shivammathur/setup-php@bf6b4fbd49ca58e4608c9c89fba0b8d90bd2a39f # 2.35.5
@@ -118,6 +120,8 @@ jobs:
     steps:
       - name: Checkout code
         uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5.0.1
+        with:
+          persist-credentials: false
 
       # Updating the lists can fail intermittently, typically after Microsoft has released a new package.
       # This should not be blocking for this job, so ignore any errors from this step.

.github/workflows/quicktest.yml

@@ -29,6 +29,8 @@ jobs:
     steps:
       - name: Checkout code
         uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5.0.1
+        with:
+          persist-credentials: false
 
       # Updating the lists can fail intermittently, typically after Microsoft has released a new package.
       # This should not be blocking for this job, so ignore any errors from this step.
@@ -122,6 +124,8 @@ jobs:
     steps:
       - name: Checkout code
         uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5.0.1
+        with:
+          persist-credentials: false
 
       # On stable PHPCS versions, allow for PHP deprecation notices.
       # Unit tests don't need to fail on those for stable releases where those issues won't get fixed anymore.

.github/workflows/test.yml

@@ -32,6 +32,8 @@ jobs:
     steps:
       - name: Checkout code
         uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5.0.1
+        with:
+          persist-credentials: false
 
       # Updating the lists can fail intermittently, typically after Microsoft has released a new package.
       # This should not be blocking for this job, so ignore any errors from this step.
@@ -177,6 +179,8 @@ jobs:
     steps:
       - name: Checkout code
         uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5.0.1
+        with:
+          persist-credentials: false
 
       - name: Setup ini config
         id: set_ini

.github/workflows/update-website.yml

@@ -51,6 +51,7 @@ jobs:
         uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5.0.1
         with:
           ref: ${{ steps.base_branch.outputs.BRANCH }}
+          persist-credentials: false
 
       - name: Install PHP
         uses: shivammathur/setup-php@bf6b4fbd49ca58e4608c9c89fba0b8d90bd2a39f # 2.35.5