[Backport 5.3.9104] Context: fix bug with result limits (#62054)

Context: fix bug with result limits (#61806)

While writing eval scripts for Cody context, I noticed that when searching
multiple repos, we sometimes we return greater than the intended number of
results. This PR makes a small fix so we always respect the result limits.

(cherry picked from commit 6a4ac36)

Co-authored-by: Julie Tibshirani <julietibs@apache.org>

internal/codycontext/context.go

@@ -302,6 +302,12 @@ func (c *CodyContextClient) getKeywordContext(ctx context.Context, args GetConte
 			mu.Lock()
 			defer mu.Unlock()
 
+			// Another caller may have already hit the limit, but we haven't yet responded
+			// to the cancellation. Return immediately in this case.
+			if len(collected) >= limit {
+				return
+			}
+
 			for _, res := range e.Results {
 				if fm, ok := res.(*result.FileMatch); ok {
 					collected = append(collected, filter(fileMatchToContextMatches(fm))...)