By default, `typeset` defines variables locally unless in the main scope.
This is specially bad when using `omz plugin load`, which happens inside
a function, so the declared variables don't continue being defined when
the function finishes and the main scope reappears.

For details and rationale, see:
https://zdharma-continuum.github.io/Zsh-100-Commits-Club/Zsh-Plugin-Standard.html

Closes #10518

This removes .gitignore plugin files and adds a force-rm of the old completion file,
which ignores any errors if the file doesn't exist.

Fixes #10183

Fixes #10190

Co-authored-by: Kapil Pau <kapilpau@hotmail.com>
Co-authored-by: CallMeLaNN <CallMeLaNN@users.noreply.github.com>