github workflows: update to v4, see https://github.blog/changelog/2023-09-22-github-actions-transitioning-from-node-16-to-node-20/

.github/workflows/book.yml

@@ -10,7 +10,7 @@ jobs:
     compile-book:
         runs-on: ubuntu-latest
         steps:
-            - uses: actions/checkout@v3
+            - uses: actions/checkout@v4
               with:
                 persist-credentials: false
                 fetch-depth: 0

.github/workflows/ci.yml

@@ -10,7 +10,7 @@ jobs:
     runs-on: ${{ matrix.os }}
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: actions-rs/toolchain@v1
         with:
           toolchain: nightly
@@ -48,7 +48,7 @@ jobs:
         os: [ubuntu-latest]
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: actions-rs/toolchain@v1
         with:
           toolchain: nightly
@@ -79,7 +79,7 @@ jobs:
     timeout-minutes: 30
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: actions-rs/toolchain@v1
         with:
           toolchain: nightly

.github/workflows/lints-nightly.yml

@@ -9,7 +9,7 @@ jobs:
     timeout-minutes: 30
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: actions-rs/toolchain@v1
         with:
           toolchain: nightly