Add weekly scheduled CI runs #3531

Job	Run time
features_check (ubuntu-latest)	3m 55s
no_std (ubuntu-latest, thumbv6m-none-eabi)	16s
alternative_targets (ubuntu-latest, wasm32-unknown-emscripten)	21s
rust_msrv (ubuntu-latest)	54s
no_std (ubuntu-latest, x86_64-fortanix-unknown-sgx)	16s
alternative_targets (ubuntu-latest, aarch64-apple-ios)	17s
rust_versions (ubuntu-latest, stable)	1m 11s
alternative_targets (ubuntu-latest, aarch64-linux-android)	21s
rust_versions (ubuntu-latest, beta)	56s
test_wasm (ubuntu-latest)	31s
rust_versions (ubuntu-latest, nightly)	48s
timezones (ubuntu-latest, ACST-9:30)	1m 12s
timezones (ubuntu-latest, EST4)	1m 9s
timezones (ubuntu-latest, UTC0)	1m 14s
timezones (ubuntu-latest, Asia/Katmandu)	1m 11s
timezones (macos-latest, ACST-9:30)	39s
timezones (macos-latest, EST4)	39s
timezones (macos-latest, UTC0)	55s
timezones (macos-latest, Asia/Katmandu)	39s
timezones (windows-latest, ACST-9:30)	1m 51s
timezones (windows-latest, EST4)	1m 47s
timezones (windows-latest, UTC0)	1m 37s
timezones (windows-latest, Asia/Katmandu)	1m 47s
check-docs	22s
cross-targets (x86_64-unknown-illumos)	1m 17s
cross-tests (ubuntu-latest)	1m 51s
test_wasip1 (ubuntu-latest, wasm32-wasip1)	24s
	28m 20s

Provide feedback