fix: 404 booking pages when org support is enabled locally

## What does this PR do?
Fix 404 booking pages when org support is enabled locally

## Type of change

<!-- Please delete bullets that are not relevant. -->

- Bug fix (non-breaking change which fixes an issue)

## How should this be tested?

<!-- Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration -->

-  Add localhost:3000 to ALLOWED_HOSTNAMES which is the default recommendation for enabling org support locally.
<img width="1035" alt="Screenshot 2023-07-10 at 11 04 35 AM" src="https://github.com/calcom/cal.com/assets/1780212/7272437b-afae-4073-905b-eafc39f9fafc">
- Simply restart the server and visit http://localhost:3000/pro. It will give 404. After this change it would work

## Mandatory Tasks

- [x] Make sure you have self-reviewed the code. A decent size PR without self-review might be rejected.

apps/web/test/lib/next-config.test.ts

@@ -172,9 +172,10 @@ describe("next.config.js - RegExp", () => {
 });
 
 describe("next.config.js - Org Rewrite", () => {
-  // RegExp copied from next.config.js
   const orgHostRegExp = (subdomainRegExp: string) =>
+  // RegExp copied from pagesAndRewritePaths.js orgHostPath. Do make the change there as well.
     new RegExp(`^(?<orgSlug>${subdomainRegExp})\\..*`);
+
   describe("Host matching based on NEXT_PUBLIC_WEBAPP_URL", () => {
     it("https://app.cal.com", () => {
       const subdomainRegExp = getSubdomainRegExp("https://app.cal.com");
@@ -186,6 +187,10 @@ describe("next.config.js - Org Rewrite", () => {
       expect(
         orgHostRegExp(subdomainRegExp).exec("org.cal.com")?.groups?.orgSlug
       ).toEqual("org");
+
+      expect(
+        orgHostRegExp(subdomainRegExp).exec("localhost:3000")
+      ).toEqual(null);
     });
 
     it("app.cal.com", () => {

packages/features/ee/organizations/lib/orgDomains.ts

@@ -5,6 +5,10 @@ import { ALLOWED_HOSTNAMES, RESERVED_SUBDOMAINS, WEBAPP_URL } from "@calcom/lib/
  * @param hostname
  */
 export function getOrgSlug(hostname: string) {
+  if (!hostname.includes(".")) {
+    // A no-dot domain can never be org domain. It automatically handles localhost
+    return null;
+  }
   // Find which hostname is being currently used
   const currentHostname = ALLOWED_HOSTNAMES.find((ahn) => {
     const url = new URL(WEBAPP_URL);

packages/features/test/orgDomains.test.ts

@@ -30,6 +30,14 @@ describe("Org Domains Utils", () => {
         isValidOrgDomain: false,
       });
     });
+
+    it("should return a non valid org domain for localhost", () => {
+      setupEnvs();
+      expect(orgDomainConfig("localhost:3000")).toEqual({
+        currentOrgDomain: null,
+        isValidOrgDomain: false,
+      });
+    });
   });
 
   describe("getOrgSlug", () => {