[clangd] Dont require confirmation for include-cleaner batch-fixes (#76826)

False negative/positive rate has decreased to the degree that these
extra confirmations no longer provide any value, but only create
friction in the happy case.

When we have false analysis, people usually need to apply the fixes and
run the builds to discover the failure. At that point they can add
relevant IWYU pragmas to guide analysis, and will be more likely to
create bug reports due to extra annoyance :)