ci: update GitHub Actions to v4

- Update actions/checkout@v3 → v4
- Update actions/setup-python@v4 → v5
- Update actions/upload-artifact@v3 → v4

Fixes deprecation warning and build failures

.github/workflows/build.yml

@@ -12,10 +12,10 @@ jobs:
     runs-on: windows-latest
     
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     
     - name: Set up Python
-      uses: actions/setup-python@v4
+      uses: actions/setup-python@v5
       with:
         python-version: '3.11'
     
@@ -30,7 +30,7 @@ jobs:
         pyinstaller icon_extractor.spec --clean
     
     - name: Upload artifact
-      uses: actions/upload-artifact@v3
+      uses: actions/upload-artifact@v4
       with:
         name: EU-Icon-Extractor-Windows
         path: dist/EU-Icon-Extractor.exe
@@ -49,10 +49,10 @@ jobs:
     runs-on: ubuntu-latest
     
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     
     - name: Set up Python
-      uses: actions/setup-python@v4
+      uses: actions/setup-python@v5
       with:
         python-version: '3.11'
     
@@ -72,7 +72,7 @@ jobs:
         pyinstaller icon_extractor.spec --clean
     
     - name: Upload artifact
-      uses: actions/upload-artifact@v3
+      uses: actions/upload-artifact@v4
       with:
         name: EU-Icon-Extractor-Linux
         path: dist/EU-Icon-Extractor