Add a CLI flag for disabling the command execution

[orhun]

Is your feature request related to a problem? Please describe.

The default config of git-cliff now runs typos to fix the typos in the commits:

git-cliff/cliff.toml

Lines 66 to 71 in 3c2fb60

	commit_preprocessors = [
	{ pattern = '\((\w+\s)?#([0-9]+)\)', replace = "([#${2}](<REPO>/issues/${2}))" },
	# Check spelling of the commit with https://github.com/crate-ci/typos
	# If the spelling is incorrect, it will be automatically fixed.
	{ pattern = '.*', replace_command = 'typos --write-changes -' },
	]

Thus generating a changelog for the whole git history takes some time.

Describe the solution you'd like

We should add a command-line flag for disabling command execution in the cases where the user wants to generate a changelog without running external commands.

For example, git-cliff --no-exec will skip executing the commands defined in replace_command.

Describe alternatives you've considered

None.

Additional context

See #316 for additional discussion about typos implementation.

[mamaicode]

Hey, this is still relevant?
@orhun

[orhun]

Hello @mamaicode 👋🏼

Yup, are you interested in making a PR? 🐻

[mamaicode]

Yep! Will look into this

[orhun]

Kindly ping 🐻 do you need any guidance on this?