ci: auto-approve only minor prettier-config updates

This is a follow-up for eef0e60 (#726) which enabled auto-approvals
for _all_ new versions of `@checkernetwork/prettier-config`.

Signed-off-by: Miroslav Bajtoš <oss@bajtos.net>

Author: bajtos

.github/workflows/dependabot-auto-approve-always.yml

@@ -11,6 +11,7 @@ jobs:
     strategy:
       matrix:
         dependencyStartsWith:
+          - '@checkernetwork/prettier-config'
           - '@sentry/'
           - undici
           - '@types/'