fix typos in GovernorSettings (#2957)

(cherry picked from commit ce51655c)
Signed-off-by: Hadrien Croubois <hadrien.croubois@gmail.com>

contracts/governance/extensions/GovernorSettings.sol

@@ -81,7 +81,7 @@ abstract contract GovernorSettings is Governor {
     }
 
     /**
-     * @dev Internal setter for the the voting delay.
+     * @dev Internal setter for the voting delay.
      *
      * Emits a {VotingDelaySet} event.
      */
@@ -91,7 +91,7 @@ abstract contract GovernorSettings is Governor {
     }
 
     /**
-     * @dev Internal setter for the the voting period.
+     * @dev Internal setter for the voting period.
      *
      * Emits a {VotingPeriodSet} event.
      */
@@ -103,7 +103,7 @@ abstract contract GovernorSettings is Governor {
     }
 
     /**
-     * @dev Internal setter for the the proposal threshold.
+     * @dev Internal setter for the proposal threshold.
      *
      * Emits a {ProposalThresholdSet} event.
      */