Bump github checkout action version

"The following actions uses node12 which is deprecated and will be forced to run on node16: actions/checkout@v2."

.github/workflows/freebsd.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: macos-12
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v4
     - name: make
       uses: vmactions/freebsd-vm@v0
       with:

.github/workflows/macos.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: macos-latest
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v4
     - name: make
       run: make
     - name: install check

.github/workflows/openbsd.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: macos-12
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v4
     - name: make
       uses: vmactions/openbsd-vm@v0
       with:

.github/workflows/ubuntu.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v4
     - name: make
       run: make
     - name: install check
@@ -25,7 +25,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v4
     - uses: nttld/setup-ndk@v1
       with:
         ndk-version: r21e

.github/workflows/windows.yml

@@ -15,7 +15,7 @@ jobs:
         shell: msys2 {0}
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v4
     - uses: msys2/setup-msys2@v2
       with:
         msystem: MINGW64