[Fix] Skip UID update when in unsafe report mode

[amcaplan]

WHY are these changes introduced?

When we run app info on an app with an invalid extension TOML:

1. The TOML loading fails, but is in unsafe report mode so execution can continue
2. We replace the config with a default empty object here
3. Our code thinks there's no UID
4. It inserts a second UID into the file, making it invalid 🤦

WHAT is this pull request doing?

Skips the UID update when in unsafe report mode, as:

1. We haven't built sufficient confidence that it is correct to update
2. We probably shouldn't edit files on app info anyway!

How to test your changes?

1. Create an app with an extension and change a type (e.g. string to number) in the shopify.extension.toml file
2. Run shopify app info twice.

On the second time (on main), it will fail with a double UID error. But on this branch, if you start with a clean file, you can run it many times and not hit this issue.

Measuring impact

How do we know this change was effective? Please choose one:

• n/a - this doesn't need measurement, e.g. a linting rule or a bug-fix
• Existing analytics will cater for this addition
• PR includes analytics changes to measure impact

Checklist

• I've considered possible cross-platform impacts (Mac, Linux, Windows)
• I've considered possible documentation changes

[github-actions]

We detected some changes at packages/*/src and there are no updates in the .changeset.
If the changes are user-facing, run "pnpm changeset add" to track your changes and include them in the next release CHANGELOG.

[github-actions]

Coverage report

St.❔	Category	Percentage	Covered / Total
🟡	Statements	75.15% (+0% 🔼)	8868/11801
🟡	Branches	70.33% (+0.01% 🔼)	4310/6128
🟡	Functions	75.06%	2318/3088
🟡	Lines	75.72% (+0.01% 🔼)	8384/11073

Show files with reduced coverage 🔻

St.❔	File	Statements	Branches	Functions	Lines
🟢	... / app-event-watcher.ts	93.83% (-1.23% 🔻)	86.49% (-2.7% 🔻)	90.48%	98.61%

Test suite run success

2000 tests passing in 904 suites.

Report generated by 🧪jest coverage report action from 33999f3