🐛 Fix ListFiles caching in localrepo client

[laurentsimon]

• Please check if the PR fulfills these requirements

• Tests for the changes have been added (for bug fixes / features)
• PR title follows the guidelines defined in https://github.com/ossf/scorecard/blob/main/CONTRIBUTING.md#pr-process

• What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)
  fix

• What is the current behavior? (You can also link to an open issue here)
  see https://github.com/ossf/scorecard/runs/4040748071?check_suite_focus=true

--- FAIL: TestClient_CreationAndCaching (0.00s)
    --- FAIL: TestClient_CreationAndCaching/repo_0 (0.02s)
        client_test.go:105: Got diff:   []string{
            - 	"file0",
            - 	"dir1/file1",
            - 	"dir1/dir2/file2",
              }

• What is the new behavior (if this is a feature change)?
  tests pass

• Does this PR introduce a breaking change? (What changes might users need to make in their application due to this PR?)
  no

• Other information:

[azeemshaikh38]

Can you incorporate the changes from #1187 too?

[azeemshaikh38]

Thanks for the quick fix!

[laurentsimon]

Can you incorporate the changes from #1187 too?

absolutely. Closing it.