update GitHub Actions to use actions/checkout@v4

* Also enable manual trigger.

.github/workflows/codeql.yml

@@ -1,6 +1,8 @@
 name: CodeQL
 
 on:
+  workflow_dispatch:
+    branches: [master]
   push:
     branches: [master]
   pull_request:
@@ -20,7 +22,7 @@ jobs:
 
     steps:
     - name: Check out repository and submodules
-      uses: actions/checkout@v2
+      uses: actions/checkout@v4
       with:
         fetch-depth: 0
         submodules: recursive

.github/workflows/coverity.yml

@@ -1,6 +1,8 @@
 name: Coverity (MSVC with gnu-efi) build
 
 on:
+  workflow_dispatch:
+    branches: [master]
   push:
     branches: [master]
 
@@ -16,7 +18,7 @@ jobs:
 
     steps:
     - name: Checkout repository and submodules
-      uses: actions/checkout@v2
+      uses: actions/checkout@v4
       with:
         fetch-depth: 0
         submodules: recursive

.github/workflows/linux.yml

@@ -1,6 +1,12 @@
 name: Linux (gcc with EDK2) build
 
-on: [push, pull_request]
+on:
+  workflow_dispatch:
+    branches: [master]
+  push:
+    branches: [master]
+  pull_request:
+    branches: [master]
 
 env:
   BUILD_TYPE: RELEASE
@@ -33,7 +39,7 @@ jobs:
 
     steps:
     - name: Check out repository
-      uses: actions/checkout@v2
+      uses: actions/checkout@v4
       with:
         fetch-depth: 0
 

.github/workflows/windows.yml

@@ -1,6 +1,8 @@
 name: Windows (MSVC with gnu-efi) build
 
 on:
+  workflow_dispatch:
+    branches: [master]
   push:
     branches: [master]
   pull_request:
@@ -20,7 +22,7 @@ jobs:
 
     steps:
     - name: Check out repository and submodules
-      uses: actions/checkout@v2
+      uses: actions/checkout@v4
       with:
         fetch-depth: 0
         submodules: recursive