GHA: bump and pin actions/checkout (#575)

Author: vszakats

.github/workflows/check-quotes.yml

@@ -23,7 +23,7 @@ jobs:
     name: 'check'
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
         with:
           persist-credentials: false
 

.github/workflows/linkcheck.yml

@@ -22,7 +22,7 @@ jobs:
     name: 'check'
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
         with:
           persist-credentials: false
 

.github/workflows/mdcheck.yml

@@ -22,7 +22,7 @@ jobs:
     name: 'check'
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
         with:
           persist-credentials: false
 

.github/workflows/pdf.yml

@@ -23,7 +23,7 @@ jobs:
     name: 'build'
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
         with:
           persist-credentials: false
 

.github/workflows/proselint.yml

@@ -22,7 +22,7 @@ jobs:
     name: 'check'
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
         with:
           persist-credentials: false
 

.github/workflows/spellcheck.yml

@@ -23,7 +23,7 @@ jobs:
     name: 'check'
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
         with:
           persist-credentials: false
 

.github/workflows/verify-titles.yml

@@ -23,7 +23,7 @@ jobs:
     name: 'check'
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
         with:
           persist-credentials: false
 

.github/workflows/wordcheck.yml

@@ -22,7 +22,7 @@ jobs:
     name: 'check'
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
         with:
           persist-credentials: false