fix(ci): use correct go version in CI

Author: buchdag

.github/workflows/assets.yml

@@ -17,7 +17,7 @@ jobs:
 
       - uses: actions/setup-go@v2
         with:
-          go-version: '1.17'
+          go-version: '1.18'
 
       - name: Build release assets
         run: make release

.github/workflows/tests.yml

@@ -26,7 +26,7 @@ jobs:
 
       - uses: actions/setup-go@v2
         with:
-          go-version: '1.17'
+          go-version: '1.18'
 
       - name: Install dependencies
         run: make get-deps