Pin Task version to 3.9.0

Task 3.9.1 has an issue with the PATH environment variable on Windows
(it is not correctly expanded in subcommands and go fails to find gcc).

Author: Giuseppe Lumia

Diff for: .github/workflows/release-go-task.yml

@@ -39,7 +39,7 @@ jobs:
         uses: arduino/setup-task@v1
         with:
           repo-token: ${{ secrets.GITHUB_TOKEN }}
-          version: 3.x
+          version: 3.9.0
 
       - name: Build
         run: task dist:all

Diff for: .github/workflows/test-go-task.yml

@@ -86,7 +86,7 @@ jobs:
         uses: arduino/setup-task@v1
         with:
           repo-token: ${{ secrets.GITHUB_TOKEN }}
-          version: 3.x
+          version: 3.9.0
 
       - name: Run tests
         env: