CI: bump actions/checkout to v3

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: George Melikov <mail@gmelikov.ru>
Closes #14018

.github/workflows/checkstyle.yaml

@@ -8,7 +8,7 @@ jobs:
   checkstyle:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
       with:
         ref: ${{ github.event.pull_request.head.sha }}
     - name: Install dependencies

.github/workflows/zfs-tests-functional.yml

@@ -12,7 +12,7 @@ jobs:
         os: [18.04, 20.04]
     runs-on: ubuntu-${{ matrix.os }}
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
       with:
         ref: ${{ github.event.pull_request.head.sha }}
     - name: Reclaim disk space

.github/workflows/zfs-tests-sanity.yml

@@ -8,7 +8,7 @@ jobs:
   tests:
     runs-on: ubuntu-20.04
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
       with:
         ref: ${{ github.event.pull_request.head.sha }}
     - name: Reclaim disk space

.github/workflows/zloop.yml

@@ -10,7 +10,7 @@ jobs:
     env:
       TEST_DIR: /var/tmp/zloop
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
       with:
         ref: ${{ github.event.pull_request.head.sha }}
     - name: Install dependencies