Add workaround for golang/go#44129

Signed-off-by: Thomas Stromberg <[email protected]>

Author: tstromberg

.github/workflows/ci.yaml

@@ -17,6 +17,9 @@ jobs:
         go-version: '1.16'
     - name: goimports
       run: go get golang.org/x/tools/cmd/goimports && goimports -d . | (! grep .)
+    # Workaround for missing checksums caused by https://github.com/golang/go/issues/44129
+    - name: gomod fix
+      run: go env -w GOFLAGS=-mod=mod
     - name: go vet
       run: go vet ./...
     - name: golangci-lint