ci: update actions to newer versions

.github/workflows/c-cpp.yml

@@ -80,7 +80,7 @@ jobs:
       GH_CROSSCOMPILING: ${{ matrix.cross }}
     steps:
     - name: Checkout
-      uses: actions/checkout@v4
+      uses: actions/checkout@v6
       with:
         submodules: recursive
     - name: Install dependencies
@@ -90,7 +90,7 @@ jobs:
         FWGS_PFX_PASSWORD: ${{ secrets.FWGS_PFX_PASSWORD }}
       run: bash scripts/gha/build_${{ matrix.targetos }}.sh
     - name: Upload engine (artifacts)
-      uses: actions/upload-artifact@v4
+      uses: actions/upload-artifact@v7
       with:
         name: artifact-${{ matrix.targetos }}-${{ matrix.targetarch }}
         path: artifacts/*
@@ -106,7 +106,7 @@ jobs:
       options: --privileged
     steps:
     - name: Checkout
-      uses: actions/checkout@v4
+      uses: actions/checkout@v6
       with:
         submodules: recursive
     - name: Build flatpak (Compat.i386)
@@ -121,7 +121,7 @@ jobs:
     if: ${{ github.event_name == 'push' }}
     steps:
     - name: Checkout
-      uses: actions/checkout@v4
+      uses: actions/checkout@v6
     - name: Remove old release, fetch artifacts, repackage binaries and upload new release
       env:
         GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}