[clang-tidy] `bugprone-use-after-move`: Fix handling of moves in lambda captures

Previously, we were treating a move in the lambda capture as if it happened
within the body of the lambda, not within the function that defines the lambda.

This fixes the same bug as https://reviews.llvm.org/D119165 (which it appears
may have been abandoned by the author?) but does so more simply.

Reviewed By: njames93

Differential Revision: https://reviews.llvm.org/D126780