ci: delete irrelevant trigger from all workflows

The push trigger for branches matching to the `[0-9].[0-9]+` pattern
was removed due to changing the name policy for supported branches
(2.10 -> release/2.10, 2.11 -> release/2.11).

NO_DOC=ci
NO_TEST=ci
NO_CHANGELOG=ci

(cherry picked from commit ba0a9f07)