Both the directory handle and the path are newly allocated resources which the caller now owns.
pub fn findZigLibDir(gpa: Allocator, io: Io) !Cache.Directory
pub fn findZigLibDir(gpa: Allocator, io: Io) !Cache.Directory {
const cwd_path = try getResolvedCwd(io, gpa);
defer gpa.free(cwd_path);
const self_exe_path = try std.process.executablePathAlloc(io, gpa);
defer gpa.free(self_exe_path);
return findZigLibDirFromSelfExe(gpa, io, cwd_path, self_exe_path);
}