Test that fee currency is used in tx pool

Before, the gas price was always sufficiently high in all e2e tests to
mask certain cases of bad fee currency handling in the tx pool.

e2e_test/js-tests/test_viem_tx.mjs

@@ -270,4 +270,28 @@ describe("viem send tx", () => {
 			}
 		}
 	}).timeout(10_000);
+
+	it("send fee currency tx with just high enough gas price", async () => {
+		const block = await publicClient.getBlock({});
+		// Actually, the base fee will be a bit lower next block, since our blocks
+		// are always mostly empty. But the difference will be much less than the
+		// exchange rate of 2, so the test will still check that we take the fee
+		// currency into account everywhere.
+		const maxFeePerGas = block.baseFeePerGas / 2n;
+		const request = await walletClient.prepareTransactionRequest({
+			account,
+			to: "0x00000000000000000000000000000000DeaDBeef",
+			value: 2,
+			gas: 90000,
+			feeCurrency: process.env.FEE_CURRENCY2,
+			maxFeePerGas,
+			maxPriorityFeePerGas: 1n,
+		});
+		const signature = await walletClient.signTransaction(request);
+		const hash = await walletClient.sendRawTransaction({
+			serializedTransaction: signature,
+		});
+		const receipt = await publicClient.waitForTransactionReceipt({ hash });
+		assert.equal(receipt.status, "success", "receipt status 'failure'");
+	}).timeout(5_000);
 });

e2e_test/shared.sh

@@ -11,6 +11,7 @@ export REGISTRY_ADDR=0x000000000000000000000000000000000000ce10
 export TOKEN_ADDR=0x471ece3750da237f93b8e339c536989b8978a438
 export FEE_CURRENCY_DIRECTORY_ADDR=0x9212Fb72ae65367A7c887eC4Ad9bE310BAC611BF
 export FEE_CURRENCY=0x000000000000000000000000000000000000ce16
+export FEE_CURRENCY2=0x000000000000000000000000000000000000ce17
 export FEE_HANDLER=0xcd437749e43a154c07f3553504c68fbfd56b8778
 export ORACLE3=0xbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb0003