Since `set -e` is enabled, when `commit.gpgsign` is not set the
`git config` command would show an error. Given that it is technically
not ignored, the subshell would exit.

With this change, the `commit.gpgsign` setting is properly tested
by doing the fallback test if the command fails, so no exit status
code ends up quiting the subshell.

Co-authored-by: Marc Cornellà <hello@mcornella.com>

The commands `omz plugin {enable,disable}` and `omz theme set`
automatically reload the zsh session on success. With this
change, the CLI checks whether the commands are run in an
interactive session before reloading the zsh session.

This change also conditionally sets the completion function
for `omz` so that it's not done in a non-interactive session.

Fixes #9737

Fixes #10520

BREAKING CHANGE: the `zsh_reload` plugin is deprecated. Instead of using its `src`
function, use `omz reload` or `exec zsh` to reload zsh after making changes to
your `.zshrc` file.

Closes #9078

Fixes #9540

Fixes #9087

Co-authored-by: Marc Cornellà <hello@mcornella.com>

Fixes #9672
Co-authored-by: Marc Cornellà <hello@mcornella.com>

* Don't error on upgrade no-op

No error code is required for a non failure scenario.

* Manually check whether changes were pulled in `omz update`
Co-authored-by: Marc Cornellà <hello@mcornella.com>

Co-authored-by: Fernando Crespo <fxcrespo@iMac-44054.local>
Co-authored-by: Marc Cornellà <marc.cornella@live.com>

Zsh versions older than 5.3 don't have ZSH_ARGZERO, so use an alternative
method to get the zsh command.

Fixes #9558

Fixes #9495

See https://github.com/ohmyzsh/ohmyzsh/issues/9087#issuecomment-712460275