chore(db): remove 23 unused database methods (#22999)

Removes 22 database query methods with no callers outside generated code
and the dbauthz wrapper layer (~1,600 lines).

**Security keys (6)** — superseded by `cryptokeys` package:
`GetAppSecurityKey`, `UpsertAppSecurityKey`, `GetOAuthSigningKey`,
`UpsertOAuthSigningKey`, `GetCoordinatorResumeTokenSigningKey`,
`UpsertCoordinatorResumeTokenSigningKey`

**Superseded queries (4):**
- `GetProvisionerJobsByIDs` → `GetProvisionerJobsByIDsWithQueuePosition`
- `GetDeploymentDAUs` / `GetTemplateDAUs` →
`GetTemplateInsightsByInterval`
- `GetWorkspaceBuildParametersByBuildIDs` + its `GetAuthorized...`
variant → unused

**OAuth2 (2):**
`GetOAuth2ProviderAppByRegistrationToken`,
`UpdateOAuth2ProviderAppSecretByID`

**Chat (4)** — pre-wired with no callers:
`GetChatModelConfigByProviderAndModel`, `DeleteChatMessagesByChatID`,
`ListChatsByRootID`, `ListChildChatsByParentID`

**Other (6):**
`DeleteGitSSHKey`, `UpdateUserLinkedID`, `GetFileIDByTemplateVersionID`,
`GetTemplateVersionHasAITask`, `InsertUserGroupsByName`,
`RemoveUserFromAllGroups`

coderd/database/queries/user_links.sql

@@ -37,14 +37,6 @@ INSERT INTO
 VALUES
 	( $1, $2, $3, $4, $5, $6, $7, $8, $9 ) RETURNING *;
 
--- name: UpdateUserLinkedID :one
-UPDATE
-	user_links
-SET
-	linked_id = $1
-WHERE
-	user_id = $2 AND login_type = $3 RETURNING *;
-
 -- name: UpdateUserLink :one
 UPDATE
 	user_links