build: go 1.24

We were running behind and there were quite some deprecations to update.
This was mostly in the upstream copy/pasta package but seems quite
minimal.

vendor/github.com/charmbracelet/x/cellbuf/utils.go

@@ -0,0 +1,38 @@
+package cellbuf
+
+import (
+	"strings"
+)
+
+// Height returns the height of a string.
+func Height(s string) int {
+	return strings.Count(s, "\n") + 1
+}
+
+func min(a, b int) int { //nolint:predeclared
+	if a > b {
+		return b
+	}
+	return a
+}
+
+func max(a, b int) int { //nolint:predeclared
+	if a > b {
+		return a
+	}
+	return b
+}
+
+func clamp(v, low, high int) int {
+	if high < low {
+		low, high = high, low
+	}
+	return min(high, max(low, v))
+}
+
+func abs(a int) int {
+	if a < 0 {
+		return -a
+	}
+	return a
+}