Spring Support "--" end of options in SimpleCommandLineArgsParser

Prior to this commit, the SimpleCommandLineArgsParser would reject "--" arguments as invalid. As reported by the community, the POSIX utility conventions (Guideline 10) state that

The first -- argument that is not an option-argument should be accepted as a delimiter indicating the end of options. Any following arguments should be treated as operands, even if they begin with the '-' character.

This commit updates SimpleCommandLineArgsParser to not reject "--" arguments and instead to consider remaining arguments as non-optional.

Fixes gh-21949

Comment From: bclozel

Thanks @reevik , I've updated my PR.