Fix Python Functions error when path has spaces (#5831)

Proposed fix for #5830 

Issue seems to be caused by [spawn](https://github.com/firebase/firebase-tools/blob/f8f19dc060e6daf060b87d38fd2a38d24bab8210/src/functions/python.ts#L38) raising an error when path provided has spaces. Might be related to nodejs/node#38490. 

### Scenarios Tested

Similar to steps provided in #5830 

1. Run `mkdir 'i like spaces'`
2. Run `cd i\ like\ spaces` or `cd 'i like spaces'`
3. Run `firebase init functions --project <project_id>`
    1. Select `Python`
    2. Do you want to install dependencies now? Yes
4. Run `cd functions`
5. Run `firebase emulators:start`
    1. Emulators start with no issues
7. Uncomment code in `main.py` to deploy
8. Run `firebase deploy --only functions`
    1. Functions deployed with no issues

### Sample Commands

`firebase emulators:start` && `firebase deploy --only functions`

Author: aalej

CHANGELOG.md

@@ -1 +1,2 @@
 - Fixes an issue in the EventArc emualtor where events missing optional fields would cause crashes. (#5803)
+- Fixes an issue running `firebase emulators:start` and `firebase deploy` when Python Cloud Functions directory path has spaces. (#5830)

src/functions/python.ts

@@ -14,7 +14,7 @@ export const DEFAULT_VENV_DIR = "venv";
 export function virtualEnvCmd(cwd: string, venvDir: string): { command: string; args: string[] } {
   const activateScriptPath =
     process.platform === "win32" ? ["Scripts", "activate.bat"] : ["bin", "activate"];
-  const venvActivate = path.join(cwd, venvDir, ...activateScriptPath);
+  const venvActivate = `"${path.join(cwd, venvDir, ...activateScriptPath)}"`;
   return {
     command: process.platform === "win32" ? venvActivate : ".",
     args: [process.platform === "win32" ? "" : venvActivate],