Remove repetitive words in the docs (#4944)

Signed-off-by: cuinix <915115094@qq.com>

CHANGELOG.md

@@ -676,7 +676,7 @@ It is no longer possible to call an `initializer`-protected function from within
 This release includes two small breaking changes in `TimelockController`.
 
 1. The `onlyRole` modifier in this contract was designed to let anyone through if the role was granted to `address(0)`,
-   allowing the possibility to to make a role "open", which can be used for `EXECUTOR_ROLE`. This modifier is now
+   allowing the possibility to make a role "open", which can be used for `EXECUTOR_ROLE`. This modifier is now
    replaced by `AccessControl.onlyRole`, which does not have this ability. The previous behavior was moved to the
    modifier `TimelockController.onlyRoleOrOpenRole`.
 2. It was possible to make `PROPOSER_ROLE` an open role (as described in the previous item) if it was granted to

contracts/utils/math/Math.sol

@@ -440,7 +440,7 @@ library Math {
 
             // We now have x_n such that `x_n = 2**(e-1) ≤ sqrt(a) < 2**e = 2 * x_n`. This implies ε_n ≤ 2**(e-1).
             //
-            // We can refine our estimation by noticing that the the middle of that interval minimizes the error.
+            // We can refine our estimation by noticing that the middle of that interval minimizes the error.
             // If we move x_n to equal 2**(e-1) + 2**(e-2), then we reduce the error to ε_n ≤ 2**(e-2).
             // This is going to be our x_0 (and ε_0)
             xn = (3 * xn) >> 1; // ε_0 := | x_0 - sqrt(a) | ≤ 2**(e-2)