Make the test timeout configurable

The test timeouts were previously hardcoded to 60s for playback tests and 240s
while recording. Recording the tests has been takes ~5 minutes on CI and
bumping into this timeout. This PR updates the default while recording to 10
minutes and makes it configurable with a `TEST_TIMEOUT` environment variable.
If `TEST_TIMEOUT` is a raw number, the units will be assumed to be seconds. You
can also specify a units suffix like `TEST_TIMEOUT=10m`.

Merges #148

LGTM given by: @KPreisner

ava.config.mjs

@@ -7,17 +7,33 @@ const __filename = fileURLToPath(import.meta.url);
 const __dirname = path.dirname(__filename);
 process.env.TSX_TSCONFIG_PATH = path.join(__dirname, "tsconfig.test.json");
 
+let timeout;
+if (process.env.TEST_TIMEOUT) {
+  // Allow the timeout to be specified with the `TEST_TIMEOUT` environment variable.
+  timeout = process.env.TEST_TIMEOUT;
+  // Default to seconds if no unit is specified.
+  if (/^\d+$/.test(timeout)) {
+    timeout = `${timeout}s`;
+  }
+} else {
+  // Set the default fallback timeout and increase it if we expect to make live API calls.
+  if (
+    ["dryrun", "record", "update", "wild"].includes(
+      process.env.NOCK_BACK_MODE ?? "lockdown",
+    )
+  ) {
+    timeout = "10m";
+  } else {
+    timeout = "60s";
+  }
+}
+
 export default {
   extensions: {
     ts: "module",
   },
   files: ["test/**/*.test.ts"],
-  // Increase the timeout if we expect to make live API calls.
-  timeout: ["dryrun", "record", "update", "wild"].includes(
-    process.env.NOCK_BACK_MODE ?? "lockdown",
-  )
-    ? "240s"
-    : "60s",
+  timeout,
   // Use child processes instead of threads because notch isn't thread safe.
   workerThreads: false,
 };