[CI] MSVC sccache auth issues

[alliepiper]

sccache auth has been failing on Windows CI seemingly at random lately.

[alliepiper]

@trxcllnt noticed that this could happen if our AWS creds have special characters that need escaping here.

[alliepiper]

Maybe switching to file-based auth like we do for linux would be simpler than trying to figure out how to pass these strings through powershell, bash, docker, and github-actions simultaneously 😅