[clangd] Disable crashy unchecked-optional-access tidy check (#69427)

Fixes llvm/llvm-project#69369.
Fixes clangd/clangd#1700.

(cherry picked from commit e63ab13c82e78f65baca48d5b5e4f6ea8d55dbc7)

Author: kadircet

clang-tools-extra/clangd/TidyProvider.cpp

@@ -219,6 +219,9 @@ TidyProvider disableUnusableChecks(llvm::ArrayRef<std::string> ExtraBadChecks) {
       "-bugprone-use-after-move",
       // Alias for bugprone-use-after-move.
       "-hicpp-invalid-access-moved",
+      // Check uses dataflow analysis, which might hang/crash unexpectedly on
+      // incomplete code.
+      "-bugprone-unchecked-optional-access",
 
       // ----- Performance problems -----