[clang-tools-extra] [NFC][clangd][test] add clang-tidy config to ensure test cases sandbox (PR #141410)

[kadir çetinkaya via cfe-commits]

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@@ -0,0 +1 @@
+InheritParentConfig: false
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kadircet wrote:

are we running any tests in this directory? these inputs are usually copied to temp test directories, since you're not copying this over in any of the tests, is this really needed? (or do we have some tests that recursively copy everything?)

https://github.com/llvm/llvm-project/pull/141410