internal/lsp/cache: remove unsynchronized write to snapshot.files

snapshot.GetVersionedFile already memoizes the file handle in
snapshot.files. There is no reason to do another write, and this write
is unsynchronized.

Fixes golang/go#50747

Change-Id: Ib196395135de6f22dd59169accb756665ad10e58
Reviewed-on: https://go-review.googlesource.com/c/tools/+/380214
Trust: Robert Findley <rfindley@google.com>
Run-TryBot: Robert Findley <rfindley@google.com>
Reviewed-by: Bryan Mills <bcmills@google.com>
gopls-CI: kokoro <noreply+kokoro@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

internal/lsp/cache/view.go

@@ -396,11 +396,10 @@ func (s *snapshot) locateTemplateFiles(ctx context.Context) {
 		excluded := pathExcludedByFilter(relpath, dir, s.view.gomodcache, s.view.options)
 		if fileHasExtension(path, suffixes) && !excluded && !fi.IsDir() {
 			k := span.URIFromPath(path)
-			fh, err := s.GetVersionedFile(ctx, k)
+			_, err := s.GetVersionedFile(ctx, k)
 			if err != nil {
 				return nil
 			}
-			s.files[k] = fh
 		}
 		searched++
 		if fileLimit > 0 && searched > fileLimit {