The Git-bundled GPG on Windows (MSYS2-based) does not automatically convert
Windows-style paths in environment variables like GNUPGHOME. This caused GPG
to fail with exit code 2 when verifying Microsoft JDK signatures on Windows,
because the GNUPGHOME path (D:\a\_temp\...) was not recognized as a valid
POSIX path.
Fix: pass --homedir as an explicit command-line argument to both gpg --import
and gpg --verify. MSYS2 does correctly convert Windows paths in command-line
arguments, so this approach works reliably on Windows, Linux, and macOS.
801240703e