Fix typo in CHANGELOG (#3138)

Remove repeated word "the".

(cherry picked from commit ae54e6d)
Signed-off-by: Hadrien Croubois <hadrien.croubois@gmail.com>

CHANGELOG.md

@@ -2,7 +2,7 @@
 
 ## 4.5.0
 
- * `ERC2891`: add implementation of the royalty standard, and the respective extensions for `ERC721` and `ERC1155`. ([#3012](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3012))
+ * `ERC2981`: add implementation of the royalty standard, and the respective extensions for `ERC721` and `ERC1155`. ([#3012](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3012))
  * `GovernorTimelockControl`: improve the `state()` function to have it reflect cases where a proposal has been canceled directly on the timelock. ([#2977](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/2977))
  * Preset contracts are now deprecated in favor of [Contracts Wizard](https://wizard.openzeppelin.com). ([#2986](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/2986))
  * `Governor`: add a relay function to help recover assets sent to a governor that is not its own executor (e.g. when using a timelock). ([#2926](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/2926))