fix(ReactionUserManager): remove before query option

[almostSouji]

Please describe the changes this PR makes and why it should be merged:

The before option is apparently not actually supported as per discord/discord-api-docs#1324 (comment) (despite documented)

Status and versioning classification:

• Code changes have been tested against the Discord API, or there are no code changes
• I know how to update typings and have done so, or typings don't need updating
• This PR includes breaking changes (methods removed or renamed, parameters moved or removed)

[papaia]

This PR includes breaking changes (methods removed or renamed, parameters moved or removed)

But you labeled it semver: patch.

[almostSouji]

Technically breaking, because it removes something from the interface
But it is a bug fix, seeing that it removes an unsupported option

Unsure which applies.

[papaia]

The behavior won't change as that param is not respected by Discord.

[tguichaoua]

Technically breaking, because it removes something from the interface
But it is a bug fix, seeing that it removes an unsupported option

Unsure which applies.

In TypeScript, it introduce a breaking change.
playground

[papaia]

Pretty sure we don't count typescript breaks as breaking.