How do I manually run a particular cron job via the command line?

Use the sys:cron:run magerun command:

./vendor/n98/magerun2/bin sys:cron:run <cron job name>

An example:

The new syntax is:

./vendor/bin/n98-magerun2 sys:cron:run `<cron job name>`

Step 1

Install n98-magerun2

Step 2

Find out the Cron job ID:

magerun sys:cron:list

github.com/netz98/n98-magerun2/blob/7.4.0/README.md#list-cronjobs

Step 3

magerun sys:cron:run <job ID>