fix: disable upgrade notification for the manifest info command

[mwbrooks]

Changelog

Disable upgrade notification for the slack manifest info command. The command returns JSON that may be used for scripting and the upgrade notifications interfere with parsing the response output.

Summary

This pull request adds manifest info to the list of commands that suppress update notifications. The manifest info command outputs structured data consumed by other tools, so injecting an upgrade banner would corrupt the output.

Also extends isIgnoredCommand() to support multi-word subcommands (e.g., manifest info is ignored but manifest validate is not).

Preview

N/A

Testing

1. Build with an artificially old version to trigger the upgrade notification:

   go build -ldflags="-X 'github.com/slackapi/slack-cli/internal/version.Version=v1.0.0'" -o bin/slack

2. Delete the lastUpdateCheckedAt timestamp from ~/.slack/config.json so the check isn't skipped due to recency.
3. Create a project:

   ./bin/slack create my-app/
   cd my-app/

4. Verify slack manifest info does NOT show an upgrade notification:

   ./bin/slack manifest info --source local

5. Verify another command DOES show the upgrade notification.

   ./bin/slack manifest validate

Requirements

• I've read and understood the Contributing Guidelines and have done my best effort to follow them.
• I've read and agree to the Code of Conduct.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 71.66%. Comparing base (ebd9ae5) to head (f57f876).

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #548      +/-   ##
==========================================
+ Coverage   71.64%   71.66%   +0.01%     
==========================================
  Files         225      225              
  Lines       19066    19068       +2     
==========================================
+ Hits        13660    13665       +5     
+ Misses       4202     4199       -3     
  Partials     1204     1204              

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[zimeg]

@mwbrooks LGTM! And thanks for saving confusion or error 🙏

I'm leaving a question that's alright to ignore and a praise for keeping code health improving constant! Please let's get this merged when time is right.

[zimeg]

Suggested change

	ignoredCommands := []string{"_fingerprint", "api", "manifest info", "version"}
	ignoredCommands := []string{"_fingerprint", "api", "manifest", "manifest info", "version"}

🪬 question: Is the shortened command automatic? I prefer extended commands often in scripts but am unsure if this should be covered too.

[zimeg]

👁️‍🗨️ praise: Thanks! This makes me think much about tests as spec more than unit.