chore: removed unsupported samples

[munkhuushmgl]

go/cloud-ai-2021-snippet-cleanup

Devsite update: cl/362403058

the following region tag needs to be deleted on github first, then sample browser can regenerate. Otherwise, sample browser does not have an option to remove specific language support from a generated page.
vision_crop_hint_detection

[snippet-bot]

Here is the summary of possible violations 😱

Details

There is a possible violation for removing region tag in use.

• vision/src/detect_crop_hints.php:18, tag vision_crop_hint_detection(usage: page 1).

The end of the violation section. All the stuff below is FYI purposes only.

---

You are about to delete the following sample browser page.

• vision/src/detect_crop_hints.php:18, tag vision_crop_hint_detection(usage: page 1).

---

Here is the summary of changes.

You are about to delete 2 region tags.

• vision/src/detect_crop_hints.php:18, tag vision_crop_hint_detection
• vision/src/detect_crop_hints_gcs.php:18, tag vision_crop_hint_detection_gcs

---

This comment is generated by snippet-bot.
If you find problems with this result, please file an issue at:
https://github.com/googleapis/repo-automation-bots/issues.
To update this comment, add snippet-bot:force-run label or use the checkbox below:

• Refresh this comment