Bump actions/upload-artifact from 6 to 7 (#8963)

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 6 to 7.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](https://github.com/actions/upload-artifact/compare/v6...v7)

---
updated-dependencies:
- dependency-name: actions/upload-artifact
  dependency-version: '7'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/build.yml

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index f6bc138..ac955bf 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -42,7 +42,7 @@
         chmod +x flatc
         ./flatc --version
     - name: upload build artifacts
-      uses: actions/upload-artifact@v6
+      uses: actions/upload-artifact@v7
       with:
         name: Linux flatc binary ${{ matrix.cxx }}
         path: flatc
@@ -170,7 +170,7 @@
     - name: test
       run: Release\flattests.exe
     - name: upload build artifacts
-      uses: actions/upload-artifact@v6
+      uses: actions/upload-artifact@v7
       with:
         name: Windows flatc binary
         path: Release\flatc.exe
@@ -246,7 +246,7 @@
         chmod +x Release/flatc
         Release/flatc --version
     - name: upload build artifacts
-      uses: actions/upload-artifact@v6
+      uses: actions/upload-artifact@v7
       with:
         name: Mac flatc binary Intel
         path: Release/flatc
@@ -289,7 +289,7 @@
         chmod +x Release/flatc
         Release/flatc --version
     - name: upload build artifacts
-      uses: actions/upload-artifact@v6
+      uses: actions/upload-artifact@v7
       with:
         name: Mac flatc binary Universal
         path: Release/flatc
@@ -373,7 +373,7 @@
     - name: Run benchmarks
       run: ./flatbenchmark --benchmark_repetitions=5 --benchmark_display_aggregates_only=true --benchmark_out_format=console --benchmark_out=benchmarks/results_${{matrix.cxx}}
     - name: Upload benchmarks results
-      uses: actions/upload-artifact@v6
+      uses: actions/upload-artifact@v7
       with:
         name: Linux flatbenchmark results ${{matrix.cxx}}
         path: benchmarks/results_${{matrix.cxx}}

.github/workflows/main.yml

diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 5d91064..eb08715 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -27,7 +27,7 @@
        language: c++
        fuzz-seconds: 60
    - name: Upload Crash
-     uses: actions/upload-artifact@v6
+     uses: actions/upload-artifact@v7
      if: failure() && steps.build.outcome == 'success'
      with:
        name: artifacts