fix(ext/node): handle shell redirections in child_process exec (#32087)

When child_process.exec() runs a shell command like "deno" "script.js" <
"input.txt", transformDenoShellCommand failed to add run -A because
shell redirections (<, >, |) were included in the args passed to the CLI
parser, triggering the metacharacter safety bail-out.


Enables node_compat tests: test-stdin-from-file.js and
test-stdin-from-file-spawn.js.