ci: pin go-version to 1.18.7

.github/workflows/build-test.yml

@@ -12,7 +12,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ ubuntu-20.04 ]
-        go: [ '^1.17' ]
+        go: [ '1.18.7' ]
         goos: [ linux ]
         goarch: [ amd64, arm64 ]
     runs-on: ${{ matrix.os }}

.github/workflows/release.yml

@@ -11,7 +11,7 @@ jobs:
         uses: actions/checkout@v2
       - uses: actions/setup-go@v2
         with:
-          go-version: '^1.17'
+          go-version: '1.18.7'
       - name: Build
         env:
           REF: ${{ github.ref }}