Bump parking_lot from 0.12.1 to 0.12.2 #273

Job	Run time
Check it compiles on old Rust (1.31.0)	1m 48s
Verify benchmarks compile	58s
32bit tests	35s
Clippy lints	21s
Run the big ignored tests	1m 16s
Check documentation links	7s
Miri checks	7m 31s
Check formatting	7s
Check it compiles on old Rust (1.45.0)	16s
Build & test (ubuntu-latest, stable)	32s
Test with experimental-thread-local	41s
Build & test (ubuntu-latest, beta)	39s
Thread Sanitizer checks MacOS	15s
Build & test (ubuntu-latest, nightly)	42s
Build & test (macos-latest, stable)	58s
Build & test (macos-latest, beta)	49s
Build & test (macos-latest, nightly)	52s
Build & test (windows-latest, stable)	3m 19s
Build & test (windows-latest, beta)	1m 45s
Build & test (windows-latest, nightly)	1m 48s
	25m 19s

Provide feedback