Mark current go version as non stable

.github/workflows/go.yml

@@ -15,6 +15,7 @@ jobs:
       - name: Set up Go
         uses: actions/setup-go@v2
         with:
+          stable: 'false'
           go-version: 1.17-rc1
 
       - name: Build

.github/workflows/release.yml

@@ -16,6 +16,7 @@ jobs:
       - name: Set up Go
         uses: actions/setup-go@v2
         with:
+          stable: 'false'
           go-version: 1.17-rc1
       - name: Run GoReleaser
         uses: goreleaser/goreleaser-action@v2