Fix BoardGameGeek false-positive using API validation

[VivekGaddam]

Description

This PR fixes a false-positive detection for BoardGameGeek in Sherlock.

Previously, non-existent usernames were incorrectly marked as found because Sherlock only checked the profile page URL. Now, it uses the BoardGameGeek API (urlProbe) to verify the username:

• Existing usernames return a JSON object.
• Non-existent usernames return an empty list ([]).

Changes

• Updated BoardGameGeek entry in sherlock_project/resources/data.json to use urlProbe.
• Set "errorMsg": "[]" and "errorType": "message" to correctly detect invalid usernames.

Testing

Tested locally with postman
curl --location 'https://api.geekdo.com/api/users?username=username_that_does_not_exist_9999'
result:
[]

curl --location 'https://api.geekdo.com/api/users?username=vivekgaddam'
[
{
"type": "users",
"id": "4382477",
"userid": 4382477,
"username": "vivekgaddam",
"href": "/profile/vivekgaddam",
"firstname": "",
"lastname": "",
"city": "",
"state": "",
"country": "",
"isocountry": "",
"regdate": "2025-10-08",
"designerid": 0,
"publisherid": 0,
"hideSupporter": false,
"adminBadges": [],
"userMicrobadges": [],
"supportYears": [],
"hideName": false,
"links": [
{
"rel": "self",
"uri": "/api/users/4382477"
}
],
"canonical_link": "https://boardgamegeek.com/profile/vivekgaddam"
}
]

[github-actions]

Automatic validation of changes

Target	F+ Check	F- Check
BoardGameGeek	✔️   Pass	❌   Fail

---

Failures were detected on at least one updated target. Commits containing accuracy failures will often not be merged (unless a rationale is provided, such as false negatives due to regional differences).

[VivekGaddam]

Yeah okay! can i work spotify ? i see no PR on that.

[ppfeister]

If it's not present, or is experiencing issues, go right ahead. No need to ask (but we don't assign issues for site changes)

For major codebase changes, always open an issue first to make sure it's actually wanted -- but site changes (data.json) are always desirable