Use mozilla-actions/sccache-action for caching builds

[ulyssa]

There seems to be something weird with with how we're using the GitHub Action cache that both @kpfleming and I have hit today that's breaking the test CI. I've had a good experience using mozilla-actions/sccache-action elsewhere, so I've made this PR to try out using it instead of saving and restoring the target/ directories. I've adjusted actions/cache to only save ~/.cargo/registry.

[ulyssa]

I ran the GitHub Action initially here, and then pushed a commit with an amended timestamp to get a new SHA so that it would run again using the cache it had created.

That re-ran here, but hit what looks like a test flake on macos-13 in cli/tests/integration/async_io.rs. I reran the job here.

The first initial run reported a total duration of 17m 54s, and the third run took 13m 58s. The "Post Run sccache-cache" step prints out stats about reuse. For example:

2024-07-26T21:37:43.6188195Z [command]/opt/hostedtoolcache/sccache/0.8.1/x64/sccache --show-stats --stats-format=json
2024-07-26T21:37:43.6221189Z {"stats":{"compile_requests":596,"requests_unsupported_compiler":0,"requests_not_compile":3,"requests_not_cacheable":171,"requests_executed":422,"cache_errors":{"counts":{},"adv_counts":{}},"cache_hits":{"counts":{"Rust":238,"C/C++":42},"adv_counts":{"rust":238,"c [gcc]":42}},"cache_misses":{"counts":{"Rust":130,"C/C++":2},"adv_counts":{"c [gcc]":2,"rust":130}},"cache_timeouts":0,"cache_read_errors":0,"non_cacheable_compilations":0,"forced_recaches":0,"cache_write_errors":125,"cache_writes":7,"cache_write_duration":{"secs":4,"nanos":367548795},"cache_read_hit_duration":{"secs":110,"nanos":338469583},"compiler_write_duration":{"secs":332,"nanos":92611740},"compile_fails":10,"not_cached":{"-":36,"unknown source language":14,"incremental":4,"missing input":4,"crate-type":113},"dist_compiles":{},"dist_errors":0},"cache_location":"ghac, name: sccache-v0.8.1, prefix: /sccache/","cache_size":null,"max_cache_size":null,"use_preprocessor_cache_mode":false,"version":"0.8.1"}
2024-07-26T21:37:43.6225285Z ##[endgroup]
2024-07-26T21:37:43.6254045Z ##[notice]68% - 280 hits, 132 misses, 0 errors
2024-07-26T21:37:43.6261380Z 
2024-07-26T21:37:43.6261607Z Full human-readable stats:
2024-07-26T21:37:43.6261963Z Compile requests                    596
2024-07-26T21:37:43.6262315Z Compile requests executed           422
2024-07-26T21:37:43.6262634Z Cache hits                          280
2024-07-26T21:37:43.6262954Z Cache hits (C/C++)                   42
2024-07-26T21:37:43.6263513Z Cache hits (Rust)                   238
2024-07-26T21:37:43.6263833Z Cache misses                        132
2024-07-26T21:37:43.6264143Z Cache misses (C/C++)                  2
2024-07-26T21:37:43.6264447Z Cache misses (Rust)                 130
2024-07-26T21:37:43.6264766Z Cache timeouts                        0
2024-07-26T21:37:43.6265083Z Cache read errors                     0
2024-07-26T21:37:43.6265410Z Forced recaches                       0
2024-07-26T21:37:43.6265734Z Cache write errors                  125
2024-07-26T21:37:43.6266053Z Compilation failures                 10
2024-07-26T21:37:43.6266379Z Cache errors                          0
2024-07-26T21:37:43.6266752Z Non-cacheable compilations            0
2024-07-26T21:37:43.6267130Z Non-cacheable calls                 171
2024-07-26T21:37:43.6267489Z Non-compilation calls                 3
2024-07-26T21:37:43.6267821Z Unsupported compiler calls            0
2024-07-26T21:37:43.6268169Z Average cache write               0.623 s
2024-07-26T21:37:43.6268544Z Average compiler                  2.515 s
2024-07-26T21:37:43.6268898Z Average cache read hit            0.394 s
2024-07-26T21:37:43.6269245Z Failed distributed compilations       0
2024-07-26T21:37:43.6269489Z 
2024-07-26T21:37:43.6269824Z Non-cacheable reasons:
2024-07-26T21:37:43.6270153Z crate-type                          113
2024-07-26T21:37:43.6270508Z -                                    36
2024-07-26T21:37:43.6270825Z unknown source language              14
2024-07-26T21:37:43.6271144Z missing input                         4
2024-07-26T21:37:43.6271452Z incremental                           4
2024-07-26T21:37:43.6271675Z 
2024-07-26T21:37:43.6271974Z Cache location                  ghac, name: sccache-v0.8.1, prefix: /sccache/
2024-07-26T21:37:43.6272444Z Version (client)                0.8.1

[elliottt]