fix(vite): Fix environment variable loading issue for Windows

[Rassilion]

This PR fixes an error that occurs when running the "vite" command on some Windows machines (We encountered this issue on 2 out of 5 of our Windows development environments, I'm not sure whats effecting it). The issue and its solution are detailed in vitest-dev/vitest#1870 (comment)

Applied the fix on affected Windows machines; the error did not reoccur.

Example output of the error;

Windows 11
node 22.2.0
vite 5.2.12
@sentry/vite-plugin 2.18.0

node:events:498
      throw er; // Unhandled 'error' event
      ^

Error: spawn undefined\System32\WindowsPowerShell\v1.0\powershell ENOENT
    at ChildProcess._handle.onexit (node:internal/child_process:286:19)
    at onErrorNT (node:internal/child_process:484:16)
    at process.processTicksAndRejections (node:internal/process/task_queues:82:21)
Emitted 'error' event on ChildProcess instance at:
    at ChildProcess._handle.onexit (node:internal/child_process:292:12)
    at onErrorNT (node:internal/child_process:484:16)
    at process.processTicksAndRejections (node:internal/process/task_queues:82:21) {
  errno: -4058,
  code: 'ENOENT',
  syscall: 'spawn undefined\\System32\\WindowsPowerShell\\v1.0\\powershell',
  path: 'undefined\\System32\\WindowsPowerShell\\v1.0\\powershell',
  spawnargs: [
    '-NoProfile',
    '-NonInteractive',
    '–ExecutionPolicy',
    'Bypass',
    '-EncodedCommand',
    'UwB0AGEAcgB0ACAAIgBoAHQAdABwADoALwAvAGwAbwBjAGEAbABoAG8AcwB0ADoAMwAwADAAMAAvACIA'
  ]
}

[lforst]

Thank you!