Remove calculateInstallBaseUrl from docs (pyodide#5770)

Author: hoodmane

docs/expected_js_docs.txt

@@ -5,7 +5,6 @@ js:module
   pyodide.ffi
 js:function
   globalThis.loadPyodide
-  pyodide.calculateInstallBaseUrl
   pyodide.canvas.getCanvas2D
   pyodide.canvas.getCanvas3D
   pyodide.canvas.setCanvas2D

src/js/load-package.ts

@@ -671,6 +671,7 @@ export function toStringArray(str: string | PyProxy | string[]): string[] {
  * exported for testing
  * @param lockFileURL
  * @returns the install base url
+ * @private
  */
 export function calculateInstallBaseUrl(lockFileURL: string) {
   // 1. If the lockfile URL includes a path with slash (file url in Node.js or http url in browser), use the directory of the lockfile URL