ci(release): squeeze extra blank lines in docs go.mod

Signed-off-by: Dorin Geman <dorin.geman@docker.com>

Author: doringeman

.github/workflows/release.yml

@@ -572,6 +572,7 @@ jobs:
           # Remove the second require block added by `go get` — the docs repo
           # only needs the direct dependency in the first require block.
           awk '/^require \(/{n++} n==2{if(/^\)/) n=3; next} n!=2' go.mod > go.mod.tmp && mv go.mod.tmp go.mod
+          cat -s go.mod > go.mod.tmp && mv go.mod.tmp go.mod
 
       - name: Create pull request
         if: steps.check-docs.outputs.changed == 'true'