Upgrade pest to 2.7.6 am: 977f5c28ca am: 566846a83c

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/pest/+/2949317

Change-Id: Iffcdb275abf6882fcd955f3b4c35fc3a93d42321
Signed-off-by: Automerger Merge Worker <[email protected]>