Changes

cd(tekton/v1): update gcp triggers for next-gen (#4191)

remove tiproxy from generic gcp triggers and set profile to `next-gen`
by default. add release-nextgen and feature/tidb-zero branch matching
for push triggers and drop tiproxy-specific resource-config from the
shared mappings.

add pingcap/tiproxy-specific triggers: expand tag filter to accept
alpha/beta and nextgen tag formats and allow release-nextgen branch
pushes.
 (commit: c325140)