chore: remove failing_sections from healthcheck (#13426)

Closes #10854.

site/src/api/typesGenerated.ts

@@ -2472,7 +2472,6 @@ export interface HealthcheckReport {
   readonly time: string;
   readonly healthy: boolean;
   readonly severity: HealthSeverity;
-  readonly failing_sections: readonly HealthSection[];
   readonly derp: DERPHealthReport;
   readonly access_url: AccessURLReport;
   readonly websocket: WebsocketReport;

site/src/testHelpers/entities.ts

@@ -2528,7 +2528,6 @@ export const MockHealth: TypesGen.HealthcheckReport = {
   time: "2023-08-01T16:51:03.29792825Z",
   healthy: true,
   severity: "ok",
-  failing_sections: [],
   derp: {
     healthy: true,
     severity: "ok",
@@ -3322,7 +3321,6 @@ export const MockSharedPortsResponse: TypesGen.WorkspaceAgentPortShares = {
 export const DeploymentHealthUnhealthy: TypesGen.HealthcheckReport = {
   healthy: false,
   severity: "ok",
-  failing_sections: [], // apparently this property is not used at all?
   time: "2023-10-12T23:15:00.000000000Z",
   coder_version: "v2.3.0-devel+8cca4915a",
   access_url: {