Add retry option to curl calls to prevent some fails

Migrated issue

Reported by: fjgarlin

Related to !385 (merged)

Problem/Motivation

I saw some jobs failing, due to getting a 429 return code on the curl calls:
- https://git.drupalcode.org/project/bluecheese/-/jobs/5911928
- https://git.drupalcode.org/project/bluecheese/-/jobs/5911856

429 is just returned when there is too much traffic happening in the server, and it has a Retry-After header. curl takes that by default if we use the --retry option.

Proposed resolution

Let's add a --retry 3 to our main snippet where we curl the external files.