build: 使用环境变量替代矩阵策略中的目标架构

- 将 matrix.target_arch 替换为 fromJson(env.TARGET_ARCH)
- 更新构建和上传/下载工件的步骤以使用新的环境变量
- 删除冗余的矩阵配置，简化工作流结构

.github/workflows/build-release.yml

@@ -12,9 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        target_arch:
-          - "mipsle-softfloat"
-          - "mipsle-hardfloat"
+        target_arch: ${{ fromJson(env.TARGET_ARCH) }}
     steps:
       - name: Checkout Code
         uses: actions/checkout@v4
@@ -34,17 +32,15 @@ jobs:
     needs: setup
     strategy:
       matrix:
-        target_arch:
-          - "mipsle-softfloat"
-          - "mipsle-hardfloat"
+        target_arch: ${{ fromJson(env.TARGET_ARCH) }}
     steps:
       - name: Checkout Code
         uses: actions/checkout@v4
 
       - name: Build
         env:
-          GOARCH: ${{ contains(matrix.target_arch, 'mipsle') && 'mipsle' || '' }}
-          GOMIPS: ${{ contains(matrix.target_arch, 'softfloat') && 'softfloat' || 'hardfloat' }}
+          GOARCH: ${{ contains(fromJson(env.TARGET_ARCH), 'mipsle') && 'mipsle' || '' }}
+          GOMIPS: ${{ contains(fromJson(env.TARGET_ARCH), 'softfloat') && 'softfloat' || 'hardfloat' }}
           CGO_ENABLED: 0
         run: |
           echo "Building for GOARCH=${GOARCH} GOMIPS=${GOMIPS}"
@@ -53,17 +49,12 @@ jobs:
       - name: Upload Artifact
         uses: actions/upload-artifact@v4
         with:
-          name: cloudflared-${{ matrix.target_arch }}
-          path: cloudflared-${{ matrix.target_arch }}
+          name: cloudflared-${{ fromJson(env.TARGET_ARCH) }}
+          path: cloudflared-${{ fromJson(env.TARGET_ARCH) }}
 
   release:
     runs-on: ubuntu-latest
     needs: build
-    strategy:
-      matrix:
-        target_arch:
-          - "mipsle-softfloat"
-          - "mipsle-hardfloat"
     steps:
       - name: Checkout Code
         uses: actions/checkout@v4
@@ -71,13 +62,13 @@ jobs:
       - name: Download Artifact
         uses: actions/download-artifact@v4
         with:
-          name: cloudflared-${{ matrix.target_arch }}
+          name: cloudflared-${{ fromJson(env.TARGET_ARCH) }}
           path: .
 
       - name: Generate SHA Sums
         run: |
           echo "Generating SHA sums for release assets..."
-          sha256sum cloudflared-${{ matrix.target_arch }} > SHA256_SUMS
+          sha256sum cloudflared-${{ fromJson(env.TARGET_ARCH) }} > SHA256_SUMS
           cat SHA256_SUMS
 
       - name: Release