ci: 升级 GitHub Actions 版本

- actions/checkout v4 → v6
- orhun/git-cliff-action v3 → v4
- 添加 GITHUB_REPO 环境变量避免 API 限流

Author: AlianBlank

.github/workflows/publish-nuget.yml

@@ -14,7 +14,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Setup .NET
         uses: actions/setup-dotnet@v4

.github/workflows/release.yml

@@ -13,7 +13,7 @@ jobs:
     if: "!startsWith(github.event.head_commit.message, 'chore(release)')"
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           fetch-depth: 0
           token: ${{ secrets.GITHUB_TOKEN }}
@@ -57,12 +57,14 @@ jobs:
 
       - name: Generate CHANGELOG
         if: steps.check.outputs.need_release == 'true'
-        uses: orhun/git-cliff-action@v3
+        uses: orhun/git-cliff-action@v4
+        id: git-cliff
         with:
           config: cliff.toml
           args: --tag ${{ steps.version.outputs.version }} --strip header
         env:
           OUTPUT: CHANGELOG.md
+          GITHUB_REPO: ${{ github.repository }}
 
       - name: Commit changes
         if: steps.check.outputs.need_release == 'true'