build: split CI and go.mod version

Downstream users would like to lower the minimum required go version,
but it would be nice to test and release with the latest go. So, use a
placeholder go version file for CI.

Signed-off-by: Casey Callendrello <c1@caseyc.net>

.github/workflows/release.yaml

@@ -19,7 +19,7 @@ jobs:
       - name: Install Go
         uses: actions/setup-go@v5
         with:
-          go-version-file: go.mod
+          go-version-file: .github/go-version
 
       - name: Build
         env:
@@ -74,7 +74,7 @@ jobs:
       - name: Install Go
         uses: actions/setup-go@v5
         with:
-          go-version-file: go.mod
+          go-version-file: .github/go-version
 
       - name: Build
         env: