refactor: replace math.Min and math.Max with built-in min/max

Reference: https://github.com/lightningnetwork/lnd/pull/9451#pullrequestreview-2580942691
Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>

contractcourt/commit_sweep_resolver.go

@@ -4,7 +4,6 @@ import (
 	"encoding/binary"
 	"fmt"
 	"io"
-	"math"
 	"sync"
 
 	"github.com/btcsuite/btcd/btcutil"
@@ -391,9 +390,7 @@ func (c *commitSweepResolver) Launch() error {
 	// expires after.
 	unlockHeight := confHeight + c.commitResolution.MaturityDelay
 	if c.hasCLTV() {
-		unlockHeight = uint32(math.Max(
-			float64(unlockHeight), float64(c.leaseExpiry),
-		))
+		unlockHeight = max(unlockHeight, c.leaseExpiry)
 	}
 
 	// Update report now that we learned the confirmation height.

contractcourt/htlc_lease_resolver.go

@@ -1,8 +1,6 @@
 package contractcourt
 
 import (
-	"math"
-
 	"github.com/btcsuite/btcd/wire"
 	"github.com/lightningnetwork/lnd/chainntnfs"
 	"github.com/lightningnetwork/lnd/channeldb"
@@ -42,9 +40,7 @@ func (h *htlcLeaseResolver) deriveWaitHeight(csvDelay uint32,
 
 	waitHeight := uint32(commitSpend.SpendingHeight) + csvDelay - 1
 	if h.hasCLTV() {
-		waitHeight = uint32(math.Max(
-			float64(waitHeight), float64(h.leaseExpiry),
-		))
+		waitHeight = max(waitHeight, h.leaseExpiry)
 	}
 
 	return waitHeight