chore: fix minor typos in specs (#6204)

Author: MoNyAvA

fv/specs/AccessControlDefaultAdminRules.spec

@@ -71,7 +71,7 @@ invariant defaultAdminRoleAdminConsistency()
 └─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┘
 */
 // Writing this as an invariant would be flagged by Certora as trivial. Writing it as a rule is just as valid: we
-// verify the is true for any state of the storage
+// verify this is true for any state of the storage
 rule ownerConsistency() {
   assert defaultAdmin() == owner();
 }

fv/specs/ERC20Wrapper.spec

@@ -65,7 +65,7 @@ invariant totalSupplyIsSmallerThanUnderlyingBalance()
             require sumOfUnderlyingBalancesLowerThanUnderlyingSupply(from, to);
         }
         preserved ERC20PermitHarness.burn(address from, uint256 amount) with (env e) {
-            // If someone can burn from the wrapper, than the invariant obviously doesn't hold.
+            // If someone can burn from the wrapper, then the invariant obviously doesn't hold.
             require from != currentContract;
             require sumOfUnderlyingBalancesLowerThanUnderlyingSupply(from, currentContract);
         }