CI: Enable Miri tests on moka::cht::* modules

[tatsuya6502]

Split from #279.

Currently, we run miri test on the CI only on the deque and timer_wheel modules under moka::common: .github/workflows/Miri.yml#L43-L53

Enable miri test on moka::cht::* modules as well.

To do it, we need to shrink the test size (number of MIR statements to execute) when testing with Miri. For example, the following single test took ~4 hours (231 minutes) on my M1 Mac:

$ time cargo +nightly miri test --lib cht::segment::tests::insertion
...
running 1 test
test cht::segment::tests::insertion ... 
...
ok  

test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 90 filtered out
...

________________________________________________________
Executed in  231.55 mins    fish           external
   usr time   90.31 mins    0.36 millis   90.31 mins
   sys time   89.41 mins    2.50 millis   89.41 mins

There are more than 20 tests under these modules.