Short option for log level should be shown without equals sign in help output

[bdabelow]

Describe the bug
Currently pants help global shows the usage of the -l short options with an equals sign:

According to this comment in #21426, short options are supposed to be used without equals sign: -ldebug instead of -l=debug. This should be reflected in the help output.

I could not find any other short option beside -l, but possibly others might also be affected.

Pants version
2.24.0.dev0

OS
Linux