Error returned by fetchImpl or constructed from a non-Error throw.
IMF subscription keys to redact.
A new Error whose message (and stack when present) have
each configured subscription key replaced with [REDACTED]. Returns the
original error untouched when no keys are configured.
Remove any configured IMF subscription keys from an Error's message and stack so that downstream
console.warn/ fallback envelopes cannot leak the secret even if the underlying fetch implementation embeds request headers in its thrown error.