fix: Corrected Registration Validation, Case-Insensitive Variable Handling, Playwright workflow (#805)

* feat(auth.js): add validation for registration endpoint using validateRegistration middleware
feat(validateRegistration.js): add middleware to validate registration based on ALLOW_REGISTRATION environment variable

* fix(config.js): fix registrationEnabled and socialLoginEnabled variables to handle case-insensitive environment variable values

* refactor(validateRegistration.js): remove console.log statement

* chore(playwright.yml): skip browser download during yarn install
chore(playwright.yml): place Playwright binaries to node_modules/@playwright/test
chore(playwright.yml): install Playwright dependencies using npx playwright install-deps
chore(playwright.yml): install Playwright chromium browser using npx playwright install chromium
chore(playwright.yml): install @playwright/test@latest using npm install -D @playwright/test@latest
chore(playwright.yml): run Playwright tests using npm run e2e:ci

* chore(playwright.yml): change npm install order and update comment

The order of the npm install commands in the "Install Playwright Browsers" step has been changed to first install @playwright/test@latest and then install chromium. Additionally, the comment explaining the PLAYWRIGHT_SKIP_BROWSER_DOWNLOAD variable has been updated to mention npm install instead of yarn install.

* chore(playwright.yml): remove commented out code for caching and add separate steps for installing Playwright dependencies and browsers

api/middleware/validateRegistration.js

@@ -0,0 +1,10 @@
+function validateRegistration(req, res, next) {
+  const setting = process.env.ALLOW_REGISTRATION?.toLowerCase();
+  if (setting === 'true') {
+    next();
+  } else {
+    res.status(403).send('Registration is not allowed.');
+  }
+}
+
+module.exports = validateRegistration;