Incompatibility with @formatjs/datetimeformat polyfill

[Titozzz]

When polyfilling Intl.DateTimeFormat with @formatjs/datetimeformat and using tzOffset, 2 issues arise:

https://github.com/formatjs/formatjs/blob/main/packages/ecma402-abstract/IsValidTimeZoneName.ts#L6
https://github.com/date-fns/tz/blob/main/src/tzOffset/index.ts#L20

1. The timezone format isn't supported by the polyfill (that is supposed to cover 100% of the spec),
   -> So who's correct ? Does the format here or there needs fixing ?

2. The cache that's added to prevent performance issues is not working when the method throws, so it will try to recreate a new format function on every call, harming performance seriously when using a JS engine that is slow regarding Intl APIs (hermes on react native)

Fixing 1) would mean 2) doesn't affect me anymore but we could still address the issue to not retry and crash everytime.

I'm open to addressing those issues in a PR, but just making just we are aligned first, thanks!

Linked issue in the other repo: formatjs/formatjs#4804