Now v4 not master in checkout.

	modified:   msys2_autotools.yml
	modified:   msys2_cmake.yml
	modified:   msys2_meson.yml

Author: davea42

.github/workflows/msys2_autotools.yml

@@ -15,7 +15,7 @@ jobs:
     env:
       PYTHONIOENCODING: "utf-8"
     steps:
-    - uses: actions/checkout@master
+    - uses: actions/checkout@v4
     - uses: msys2/setup-msys2@v2
       with:
         msystem: MINGW64

.github/workflows/msys2_cmake.yml

@@ -15,7 +15,7 @@ jobs:
     env:
       PYTHONIOENCODING: "utf-8"
     steps:
-    - uses: actions/checkout@master
+    - uses: actions/checkout@v4
     - uses: msys2/setup-msys2@v2
       with:
         msystem: MINGW64

.github/workflows/msys2_meson.yml

@@ -15,7 +15,7 @@ jobs:
     env:
       PYTHONIOENCODING: "utf-8"
     steps:
-    - uses: actions/checkout@master
+    - uses: actions/checkout@v4
     - uses: msys2/setup-msys2@v2
       with:
         msystem: MINGW64