ci: remove legacy ::set-env usage

.github/workflows/CI.yaml

@@ -33,7 +33,7 @@ jobs:
       - name: Set platform name
         run: |
           export NODE_PLATFORM_NAME=$(node -e "console.log(require('os').platform())")
-          echo "::set-env name=PLATFORM_NAME::$NODE_PLATFORM_NAME"
+          echo "PLATFORM_NAME=${NODE_PLATFORM_NAME}" >> $GITHUB_ENV
         shell: bash
 
       - name: Install llvm
@@ -42,9 +42,9 @@ jobs:
 
       - name: Set llvm path
         if: matrix.os == 'windows-latest'
-        uses: allenevans/set-env@v1.0.0
-        with:
-          LIBCLANG_PATH: 'C:\\Program Files\\LLVM\\bin'
+        run: |
+          echo "LIBCLANG_PATH=C:\\Program Files\\LLVM\\bin" >> $GITHUB_ENV
+        shell: bash
 
       - name: Install
         uses: actions-rs/toolchain@v1
@@ -155,7 +155,7 @@ jobs:
       - name: Set platform name
         run: |
           export NODE_PLATFORM_NAME=$(node -e "console.log(require('os').platform())")
-          echo "::set-env name=PLATFORM_NAME::$NODE_PLATFORM_NAME"
+          echo "PLATFORM_NAME=${NODE_PLATFORM_NAME}" >> $GITHUB_ENV
         shell: bash
 
       # Do not cache node_modules, or yarn workspace links broken