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**Security keys (6)** — superseded by `cryptokeys` package: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**Superseded queries (4):**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/oauth2.sql

@@ -115,11 +115,6 @@ INSERT INTO oauth2_provider_app_secrets (
     $6
 ) RETURNING *;
 
--- name: UpdateOAuth2ProviderAppSecretByID :one
-UPDATE oauth2_provider_app_secrets SET
-    last_used_at = $2
-WHERE id = $1 RETURNING *;
-
 -- name: DeleteOAuth2ProviderAppSecretByID :exec
 DELETE FROM oauth2_provider_app_secrets WHERE id = $1;
 
@@ -249,5 +244,3 @@ WHERE id = $1 RETURNING *;
 -- name: DeleteOAuth2ProviderAppByClientID :exec
 DELETE FROM oauth2_provider_apps WHERE id = $1;
 
--- name: GetOAuth2ProviderAppByRegistrationToken :one
-SELECT * FROM oauth2_provider_apps WHERE registration_access_token = $1;