all: replace internal rand shim with math/rand/v2

lapack/testlapack/dlasq2.go

@@ -7,12 +7,12 @@ package testlapack
 import (
 	"fmt"
 	"math"
+	"math/rand/v2"
 	"sort"
 	"testing"
 
 	"gonum.org/v1/gonum/blas"
 	"gonum.org/v1/gonum/floats"
-	"gonum.org/v1/gonum/internal/rand"
 	"gonum.org/v1/gonum/lapack"
 )
 
@@ -25,7 +25,7 @@ type Dlasq2er interface {
 func Dlasq2Test(t *testing.T, impl Dlasq2er) {
 	const tol = 1e-14
 
-	rnd := rand.New(rand.NewSource(1))
+	rnd := rand.New(rand.NewPCG(1, 1))
 	for _, n := range []int{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 25, 50} {
 		for k := 0; k < 10; k++ {
 			for typ := 0; typ <= 2; typ++ {