fix: mark github webhookSecret as optional

Signed-off-by: djamaile <rdjamaile@gmail.com>

.changeset/stale-tables-stick.md

@@ -0,0 +1,5 @@
+---
+'@backstage/integration': patch
+---
+
+Mark GitHub `webhookSecret` config property as optional. A `webhookSecret` is not required when creating a GitHub App.

packages/integration/config.d.ts

@@ -239,7 +239,7 @@ export interface Config {
          * The secret used for webhooks
          * @visibility secret
          */
-        webhookSecret: string;
+        webhookSecret?: string;
         /**
          * The client ID to use
          */

packages/integration/src/github/config.ts

@@ -92,7 +92,7 @@ export type GithubAppConfig = {
   /**
    * Webhook secret can be configured at https://github.com/organizations/$org/settings/apps/$AppName
    */
-  webhookSecret: string;
+  webhookSecret?: string;
   /**
    * Found at https://github.com/organizations/$org/settings/apps/$AppName
    */
@@ -128,7 +128,7 @@ export function readGithubIntegrationConfig(
     appId: c.getNumber('appId'),
     clientId: c.getString('clientId'),
     clientSecret: c.getString('clientSecret'),
-    webhookSecret: c.getString('webhookSecret'),
+    webhookSecret: c.getOptionalString('webhookSecret'),
     privateKey: c.getString('privateKey'),
     allowedInstallationOwners: c.getOptionalStringArray(
       'allowedInstallationOwners',