[CI:DOCS] Use checkout@v4 in GH Actions

This change will minimize renovate PR's.
Checkout is an action maintained by GitHub, so using the latest v4 action shouldn't have stability consequences.

Signed-off-by: Ashley Cui <acui@redhat.com>

.github/workflows/check_cirrus_cron.yml

@@ -44,7 +44,7 @@ jobs:
         runs-on: ubuntu-latest
         steps:
             # This is where the scripts live
-            - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4
+            - uses: actions/checkout@v4
               with:
                   repository: containers/podman
                   ref: 'main'

.github/workflows/mac-pkg.yml

@@ -98,7 +98,7 @@ jobs:
         steps.check.outputs.buildarm == 'true' ||
         steps.check.outputs.builduniversal == 'true' ||
         steps.actual_dryrun.outputs.dryrun == 'true'
-      uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4
+      uses: actions/checkout@v4
       with:
         ref: ${{steps.getversion.outputs.version}}
     - name: Set up Go

.github/workflows/release-artifacts.yml

@@ -83,7 +83,7 @@ jobs:
       if: >-
         steps.check.outputs.buildartifacts == 'true' ||
         steps.actual_dryrun.outputs.dryrun == 'true'
-      uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4
+      uses: actions/checkout@v4
       with:
         repository: containers/podman
         ref: ${{steps.getversion.outputs.version}}

.github/workflows/rerun_cirrus_cron.yml

@@ -42,7 +42,7 @@ jobs:
     cron_rerun:
         runs-on: ubuntu-latest
         steps:
-            - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4
+            - uses: actions/checkout@v4
               with:
                   # All scripts used by this workflow live in podman repo.
                   repository: "containers/podman"

.github/workflows/upload-win-installer.yml

@@ -53,7 +53,7 @@ jobs:
     # Note this purposefully checks out the same branch the action runs in, as the
     # installer build script is designed to support older releases (uses the archives
     # on the release tag).
-    - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4
+    - uses: actions/checkout@v4
     # This step is super-duper critical for the built/signed windows installer .exe file.
     # It ensures the referenced $version github release page does NOT already contain
     # this file.  Windows assigns a UUID to the installer at build time, it's assumed