Bump actions/checkout from 2 to 3

Bumps [actions/checkout](https://github.com/actions/checkout) from 2 to 3.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](https://github.com/actions/checkout/compare/v2...v3)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/check.yaml

@@ -18,7 +18,7 @@ jobs:
 
     steps:
       - name: Checkout the code
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
 
       - name: Install toolchain
         uses: actions-rs/toolchain@v1
@@ -72,7 +72,7 @@ jobs:
 
     steps:
       - name: Checkout the code
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
 
       - name: Install toolchain
         id: toolchain
@@ -117,7 +117,7 @@ jobs:
 
     steps:
       - name: Checkout the code
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
 
       - name: Install toolchain
         id: toolchain
@@ -173,7 +173,7 @@ jobs:
 
     steps:
       - name: Checkout the code
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
 
       - name: Install toolchain
         id: toolchain
@@ -217,7 +217,7 @@ jobs:
 
     steps:
       - name: Checkout the code
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
 
       - name: Install toolchain
         id: toolchain
@@ -289,7 +289,7 @@ jobs:
 
     steps:
       - name: Checkout the code
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
 
       - name: Docker meta
         id: meta

.github/workflows/docs.yaml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout the code
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
 
       - name: Setup mdBook
         uses: peaceiris/actions-mdbook@4b5ef36b314c2599664ca107bb8c02412548d79d # v1.1.14