Add `--enable=all` to ShellCheck by default

Add `--enable=all` to ShellCheck by default

Change enforced shell type from `dash` to `sh` and excluded
`SC2039` and `SC3043` by default. `local` keyword is accepted by all
POSIX shells from practical point of view. There is no need anymore
to enforce dash so `local` is accepted.

Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: szubersk <szuberskidamian@gmail.com>
Closes #13020