tests: update tests/testdata@develop, include EIP2384 config (#20746)

Includes difficulty tests for EIP2384 aka MuirGlacier.

tests/difficulty_test.go

@@ -73,6 +73,9 @@ func TestDifficulty(t *testing.T) {
 	dt.config("Constantinople", params.ChainConfig{
 		ConstantinopleBlock: big.NewInt(0),
 	})
+	dt.config("EIP2384", params.ChainConfig{
+		MuirGlacierBlock: big.NewInt(0),
+	})
 	dt.config("difficulty.json", mainnetChainConfig)
 
 	dt.walk(t, difficultyTestDir, func(t *testing.T, name string, test *DifficultyTest) {