Auto merge of rust-lang#147029 - neuschaefer:memchr-2.7.6, r=marcoieni

Update memchr to 2.7.6

memchr 2.7.6 contains a bugfix for aarch64_be.

Note: I'm not sure about how dependency updates are managed in rust.git. If something should go through another branch or will happen automatically, please let me know.

Author: bors