feat: add checkout step to all build jobs in GitHub Actions workflow

Author: definev

.github/workflows/build.yaml

@@ -11,6 +11,7 @@ jobs:
   build_web:
     runs-on: ubuntu-latest
     steps:
+      - uses: actions/checkout@v4
       - name: Set up Flutter
         uses: subosito/flutter-action@v2
         with:
@@ -34,6 +35,7 @@ jobs:
   build_web_wasm:
     runs-on: ubuntu-latest
     steps:
+      - uses: actions/checkout@v4
       - name: Set up Flutter
         uses: subosito/flutter-action@v2
         with:
@@ -51,6 +53,7 @@ jobs:
   build_ios:
     runs-on: macos-latest
     steps:
+      - uses: actions/checkout@v4
       - name: Set up Flutter
         uses: subosito/flutter-action@v2
         with:
@@ -69,6 +72,7 @@ jobs:
   build_android:
     runs-on: ubuntu-latest
     steps:
+      - uses: actions/checkout@v4
       - name: Setup JDK 11
         uses: actions/setup-java@v4
         with:
@@ -94,6 +98,7 @@ jobs:
   build_windows:
     runs-on: windows-latest
     steps:
+      - uses: actions/checkout@v4
       - name: Set up Flutter
         uses: subosito/flutter-action@v2
         with:
@@ -125,6 +130,7 @@ jobs:
   build_macos:
     runs-on: macos-latest
     steps:
+      - uses: actions/checkout@v4
       - name: Set up Flutter
         uses: subosito/flutter-action@v2
         with:
@@ -143,6 +149,7 @@ jobs:
   build_linux:
     runs-on: ubuntu-latest
     steps:
+      - uses: actions/checkout@v4
       - name: Set up Flutter
         uses: subosito/flutter-action@v2
         with: