Changes

feat: checkout enterprise-plugin with branch release-x.y.z (#2790)

To ensure the consistency of dependency package versions between tidb
and plugin, for tidb branch like release-6.1-20231229-v6.1.7, checkout
plugin with branch release-6.1.7

Signed-off-by: purelind <purelind@gmail.com>
 (commit: 4f9e01f)