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**Security keys (6)** — superseded by `cryptokeys` package: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**Superseded queries (4):**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

@@ -40,33 +40,6 @@ SELECT
 	unnest(@connection_median_latency_ms :: double precision[]) AS connection_median_latency_ms,
 	unnest(@usage :: boolean[]) AS usage;
 
--- name: GetTemplateDAUs :many
-SELECT
-	(created_at at TIME ZONE cast(@tz_offset::integer as text))::date as date,
-	user_id
-FROM
-	workspace_agent_stats
-WHERE
-	template_id = $1 AND
-	connection_count > 0
-GROUP BY
-	date, user_id
-ORDER BY
-	date ASC;
-
--- name: GetDeploymentDAUs :many
-SELECT
-	(created_at at TIME ZONE cast(@tz_offset::integer as text))::date as date,
-	user_id
-FROM
-	workspace_agent_stats
-WHERE
-	connection_count > 0
-GROUP BY
-	date, user_id
-ORDER BY
-	date ASC;
-
 -- name: DeleteOldWorkspaceAgentStats :exec
 DELETE FROM
 	workspace_agent_stats