Add missing PR links to the unreleased Breaking Changes section. (#6208)

Author: Amxx

CHANGELOG.md

@@ -2,9 +2,9 @@
 
 ### Breaking changes
 
-- `ERC1967Proxy` and `TransparentUpgradeableProxy`: Mandate initialization during construction. Deployment now reverts with `ERC1967ProxyUninitialized` if an initialize call is not provided. Developers that rely on the previous behavior and want to disable this check can do so by overriding the internal `_unsafeAllowUninitialized` function to return true.
-- `ERC721` and `ERC1155`: Prevent setting an operator for `address(0)`. In the case of `ERC721` this type of operator allowance could lead to obfuscated mint permission.
-- `RLP`: The `encode(bytes32)` function now encodes `bytes32` as a fixed size item and not as a scalar in `encode(uint256)`. Users must replace calls to `encode(bytes32)` with `encode(uint256(bytes32))` to preserve the same behavior.
+- `ERC1967Proxy` and `TransparentUpgradeableProxy`: Mandate initialization during construction. Deployment now reverts with `ERC1967ProxyUninitialized` if an initialize call is not provided. Developers that rely on the previous behavior and want to disable this check can do so by overriding the internal `_unsafeAllowUninitialized` function to return true. ([#5906](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/5906))
+- `ERC721` and `ERC1155`: Prevent setting an operator for `address(0)`. In the case of `ERC721` this type of operator allowance could lead to obfuscated mint permission. ([#6171](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/6171))
+- `RLP`: The `encode(bytes32)` function now encodes `bytes32` as a fixed size item and not as a scalar in `encode(uint256)`. Users must replace calls to `encode(bytes32)` with `encode(uint256(bytes32))` to preserve the same behavior. ([#6167](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/6167))
 
 ## 5.5.0 (2025-10-31)