cmd/evm: add support for signing transactions in the unprotected format (#23937)

* cmd/evm: add support for signing transactions in the unprotected format

* cmd/evm: simplify signing of unprotected txs

cmd/evm/t8n_test.go

@@ -195,6 +195,14 @@ func TestT8n(t *testing.T) {
 			output: t8nOutput{result: true},
 			expOut: "exp_arrowglacier.json",
 		},
+		{ // Sign unprotected (pre-EIP155) transaction
+			base: "./testdata/23",
+			input: t8nInput{
+				"alloc.json", "txs.json", "env.json", "Berlin", "",
+			},
+			output: t8nOutput{result: true},
+			expOut: "exp.json",
+		},
 	} {
 
 		args := []string{"t8n"}