Move pidfile creation from setting to web cmd package (#23285)

Creating pid file should not belong to setting package and only web
command needs that. So this PR moves pidfile creation from setting
package to web command package to keep setting package more readable.

I marked this as `break` because the PIDFile path moved. For those who
have used the pid build argument, it has to be changed.

---------

Co-authored-by: KN4CK3R <admin@oldschoolhack.me>

docs/content/doc/installation/from-source.en-us.md

@@ -159,7 +159,7 @@ using the `LDFLAGS` environment variable for `make`. The appropriate settings ar
 - For _`CustomConf`_ you should use `-X \"code.gitea.io/gitea/modules/setting.CustomConf=conf.ini\"`
 - For _`AppWorkPath`_ you should use `-X \"code.gitea.io/gitea/modules/setting.AppWorkPath=working-path\"`
 - For _`StaticRootPath`_ you should use `-X \"code.gitea.io/gitea/modules/setting.StaticRootPath=static-root-path\"`
-- To change the default PID file location use `-X \"code.gitea.io/gitea/modules/setting.PIDFile=/run/gitea.pid\"`
+- To change the default PID file location use `-X \"code.gitea.io/gitea/cmd.PIDFile=/run/gitea.pid\"`
 
 Add as many of the strings with their preceding `-X` to the `LDFLAGS` variable and run `make build`
 with the appropriate `TAGS` as above.