The issue was reported by @shuujii

Add new pool value type `IREP_TT_BIGINT` and generate integer overflow
error in the VM. In the future, `mruby` will support `Bignum` for
integers bigger than `mrb_int` (probably using `mpz`).

bug(presym): Fix mrb_cmp declaration of <=> symbol for funcall

chore: upgrade markdownlint GitHub Action node version to 14

chore: fix grammar

Upgrade to  markdownlint-cli version 0.27.1

`gmtime_r` detection logic was too strict.

chore: fix spelling

Merge mruby 3.0.0

Fix load 64-bit integer from mrb format; fix #5369

Update minimal build configuration [ci skip]

Remove unused `mrblib/init_mrblib.c`

feat: add pre-commit framework