chore: email-messages update shouldn't overwrite by default

[notnmeyer]

no overwrite-by-default behavior,

 ➜ task -- email-messages update blah --lmx "<H1>hello</H1>"

   ERROR

  At least one of the flags in the group [expected-revision-id force] is required.

exit status 1
task: Failed to run task "default": exit status 1

revision id is set the same way,

➜ task -- email-messages update blah --lmx "<H1>hello</H1>" -r blah
Updated.
...

the previous behavior (looking up and sending the most recent revision) is behind --force/-f,

➜ task -- email-messages update blah --lmx "<H1>hello</H1>" --force
Updated.
...

you cant use --force and --expected-revision-id together,

➜ task -- email-messages update blah --lmx "<H1>hello</H1>" -r blah -f

   ERROR

  If any flags in the group [expected-revision-id force] are set none of the others can be; [expected-revision-id force] were all set.

[danrowden]

Might be nicer to comma-separate the flags? [expected-revision-id, force] Not sure if that's helpful for agents but as a human, it's easier to grok

[notnmeyer]

Might be nicer to comma-separate the flags? [expected-revision-id, force] Not sure if that's helpful for agents but as a human, it's easier to grok

what you're seeing is the default formatting from cobra. its hardcoded in that format, https://github.com/spf13/cobra/blob/main/flag_groups.go#L183. we could replace their functions with our own, but meh. its currently at least consistent across commands that use flag groups.