fix: honor --dry-run in install-scripts approve and deny

[abkrim]

Closes #9992.

npm install-scripts approve <pkg> --dry-run and deny <pkg> --dry-run wrote the allowScripts entry to package.json and printed the summary in the past tense, worded identically to a real run. Both flags are documented for the command, so a preview was performing the write and giving no sign it had.

The sibling prune subcommand already gets this right, which is what made the gap look like an oversight rather than a design choice:

$ npm install-scripts prune --dry-run
Would remove 1 unused allowScripts entry:
  not-installed-pkg@9.9.9 (package not installed)

writePolicyChanges() never read the flag; runPrune() does. This reads it in the same place, skips pkg.save() when it is set, and selects the conditional wording so the summary describes what actually happened.

Changes

• lib/utils/allow-scripts-cmd.js: read dry-run in writePolicyChanges(), guard the save, pass the flag to printSummary(), and let the summary choose Would approve / Would deny over the past tense. The --json payload gains a dryRun key, mirroring the prune JSON so machine consumers can distinguish a preview from an applied change.
• test/lib/commands/install-scripts.js: four tests covering approve <pkg>, approve --all, approve --json and deny <pkg> under --dry-run.

Testing

Before the fix the four new tests fail (4 of 27 in that file). After it, test/lib/commands/install-scripts.js passes 27/27 and the full suite passes 123/123 files:

$ node_modules/.bin/tap --no-coverage
1..123
# time=27887.787ms

Coverage for the modified file is 100% statements, branches, functions and lines:

$ node_modules/.bin/tap --coverage --coverage-report=text test/lib/commands/{install-scripts,approve-scripts,deny-scripts}.js test/lib/utils/allow-scripts-prune.js
  allow-scripts-cmd.js       |     100 |      100 |     100 |     100 |

End to end, against the same reproduction as the issue:

# with the fix
$ npm install-scripts approve simple-git-hooks --dry-run
Would approve simple-git-hooks:
  added simple-git-hooks@2.14.0
$ cat package.json          # allowScripts absent — untouched

# without the flag, unchanged behaviour
$ npm install-scripts approve simple-git-hooks
Approved simple-git-hooks:
  added simple-git-hooks@2.14.0
$ cat package.json          # allowScripts written, as before

The standalone approve-scripts / deny-scripts aliases share this code path and now honor the flag as well.

[Rocin1738]

I meant to say I take for responsibility there's no excuses so don't matter once again thank you I appreciate you guys for giving me a chance

[Rocin1738]

allowScripts: summary }) [%2]