type CacheFileKeyArgs<T extends CacheFileFunction> = [
symbol: string,
alignMs: number,
...rest: DropFirst<T>
];
Extracts the key generator argument tuple from a CacheFileFunction.
The first two arguments are always symbol: string and alignMs: number (aligned timestamp),
followed by the rest of the original function's arguments.
For example, for a function type (symbol: string, arg1: number, arg2: string) => Promise<void>,
this type will produce the tuple [symbol: string, alignMs: number, arg1: number, arg2: string].