go: x/tools/gopls/internal/lsp: TestLSP failures

#!watchflakes
post <- pkg == "golang.org/x/tools/gopls/internal/lsp" && test == "TestLSP" && date < "2023-06-01"

Issue created automatically to collect these failures.

Example (log):

--- FAIL: TestLSP (397.43s)
    --- FAIL: TestLSP/MultiModule (112.62s)
        --- FAIL: TestLSP/MultiModule/Completion (80.97s)
            --- FAIL: TestLSP/MultiModule/Completion/func_rank_31_19_0 (78.35s)
                completion_test.go:31: mismatching completion items (-want +got):
                      []protocol.CompletionItem(
                    - 	{
                    - 		{
                    - 			Label:         "AA",
                    - 			Kind:          5,
...
                    - 			Kind:          5,
                    - 			Detail:        "string",
                    - 			Documentation: &protocol.Or_CompletionItem_documentation{Value: string("")},
                    - 			SortText:      "-0",
                    - 			InsertText:    "AB",
                    - 			TextEdit:      &protocol.TextEdit{},
                    - 		},
                    - 	},
                    + 	nil,
                      )

— watchflakes