ci: Update to actions/checkout@v4 from v3. (#243)

Author: waywardmonkeys

.github/workflows/main.yml

@@ -14,7 +14,7 @@ jobs:
     name: stable, Linux, shared library
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
         with:
           submodules: true
 
@@ -43,7 +43,7 @@ jobs:
     name: stable, Linux, static linking, no pkg-config
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
         with:
           submodules: true
 
@@ -72,7 +72,7 @@ jobs:
     runs-on: macos-latest
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
         with:
           submodules: true
 
@@ -101,7 +101,7 @@ jobs:
     runs-on: macos-latest
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
         with:
           submodules: true
 
@@ -126,7 +126,7 @@ jobs:
     runs-on: windows-latest
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
         with:
           submodules: true
 
@@ -146,7 +146,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
         with:
           submodules: true
 
@@ -167,7 +167,7 @@ jobs:
     runs-on: macos-latest
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
         with:
           submodules: true