Rename all scripts to gitea-runner and remove all act_runner references.
- rename all scripts
- rename systemd service file
Note that the older service needs to be remove and re-installed
the /etc folder is now /etc/gitea-runner instead of /etc/act_runner
fix restart of act runner after update
when downloading gitea or act runner it will show the version that is downlaoded.
if the same version is downloaded again and alrady exists, download will be skipped