JavaScript: remove SEMMLE_TYPESCRIPT_HOME support

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Copilot-Session: b58bba12-96d2-40c2-aaf4-d249623a385c

Author: paldepind

javascript/extractor/lib/typescript/src/typescript.js

@@ -1,7 +1 @@
-let overridePath = process.env['SEMMLE_TYPESCRIPT_HOME'];
-
-if (overridePath != null) {
-  module.exports = require(overridePath);
-} else {
-  module.exports = require('typescript');
-}
+module.exports = require('typescript');