github: workaround for action trigger bug
github: workaround for action trigger bug

https://github.community/t5/GitHub-API-Development-and/How-to-restrict-execution-of-GitHub-Actions-workflow-on-tags/td-p/29567

'tags' doesn't work; the action is executed when anything (tag,
branch, etc) is created. Let's work around.

Signed-off-by: FUJITA Tomonori <93dac1fe9c4b2a3957982200319981492ad4976e@gmail.com>

a16/gobgp,osrg/gobgp,a16/gobgp,a16/gobgp,a16/gobgp,a16/gobgp,osrg/gobgp,fujita/gobgp,j-kato/gobgp,a16/gobgp,j-kato/gobgp,osrg/gobgp,fujita/gobgp,fujita/gobgp,a16/gobgp,fujita/gobgp,j-kato/gobgp,osrg/gobgp