Make codecov only informational (always pass). (#14952)

This PR makes the codecov status always pass ✔️ so that it doesn't distract from actual CI failures in the commit CI summary.

https://docs.codecov.com/docs/commit-status#informational

cc: @davidwendt @mroeschke

Authors:
  - Bradley Dice (https://github.com/bdice)

Approvers:
  - Matthew Roeschke (https://github.com/mroeschke)
  - Vyas Ramasubramani (https://github.com/vyasr)
  - GALI PREM SAGAR (https://github.com/galipremsagar)

URL: #14952

codecov.yml

@@ -6,6 +6,7 @@ coverage:
       default:
         target: auto
         threshold: 5%
+        informational: true  # The coverage will always pass
 
 github_checks:
     annotations: true