Bump actions/upload-artifact from 3 to 4

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 3 to 4.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@v3...v4)

---
updated-dependencies:
- dependency-name: actions/upload-artifact
  dependency-version: '4'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/build-natives.yml

@@ -43,7 +43,7 @@ jobs:
                 cp libfreetype.dll ../../artifacts/x64/freetype6.dll
 
             - name: Upload Artifacts
-              uses: actions/upload-artifact@v3
+              uses: actions/upload-artifact@v4
               with:
                 name: Natives-Windows
                 path: ./artifacts
@@ -68,7 +68,7 @@ jobs:
                 lipo -thin arm64 build/libfreetype.6.dylib -output ../artifacts/arm64/freetype6.dylib
 
             - name: Upload Artifacts
-              uses: actions/upload-artifact@v3
+              uses: actions/upload-artifact@v4
               with:
                 name: Natives-MacOS
                 path: ./artifacts
@@ -97,7 +97,7 @@ jobs:
                 cp libfreetype.so ../../artifacts/x64/freetype6.so
 
             - name: Upload Artifacts
-              uses: actions/upload-artifact@v3
+              uses: actions/upload-artifact@v4
               with:
                 name: Natives-Linux(x64)
                 path: ./artifacts
@@ -133,7 +133,7 @@ jobs:
                   cp libfreetype.so /artifacts/arm64/freetype6.so
 
             - name: Upload Artifacts
-              uses: actions/upload-artifact@v3
+              uses: actions/upload-artifact@v4
               with:
                 name: Natives-Linux(arm64)
                 path: ./artifacts

.github/workflows/build-nuget.yml

@@ -73,7 +73,7 @@ jobs:
                 nuget pack OpenRA-FreeType6.nuspec -OutputDirectory ./nuget -version ${{ env.PACKAGE_VERSION }}
 
             - name: Upload NuGet package to Artifacts
-              uses: actions/upload-artifact@v3
+              uses: actions/upload-artifact@v4
               with:
                 name: NuGet Package ${{ env.PACKAGE_VERSION }}
                 path: ./nuget