Ignore go.work.sum in addition to go.work (#36049)

ignore go.work.sum in addition to go.work

This adds go.work.sum to the .gitignore in addition to go.work so that
it is not accidentally committed. The generated file is only relevant to
a local dev env.

Author: camdencheek

.gitignore

@@ -173,6 +173,7 @@ test-reports/
 
 # go workspace files shouldn't be committed
 go.work
+go.work.sum
 
 # binary
 /sg