[cli] Don't log error when running vc dev in a directory without a .g…

…it directory (#11450)

`vc dev` in a dir without a `.git` dir would display an error the user should not see:

```
Vercel CLI 34.0.0
fatal: not a git repository (or any of the parent directories): .git
> Ready! Available at [http://localhost:3000](http://localhost:3000)
```

This fixes that by ignoring the stderr from `git rev-parse`.

.changeset/cold-foxes-fry.md

@@ -0,0 +1,5 @@
+---
+'vercel': patch
+---
+
+[cli] Do not pipe git stderr to user during successful `vc dev` run

packages/cli/src/util/git-helpers.ts

@@ -37,6 +37,7 @@ export function getGitDirectory(opts: GitExecOptions): string | null {
     const gitConfigPath = execSync('git rev-parse --git-dir', {
       cwd,
       encoding: 'utf8',
+      stdio: ['ignore', 'pipe', 'ignore'],
     });
 
     return gitConfigPath;