autobuild-action: Run autobuilders with $CODEQL_RUNNER set.

Without this, the tracer will not be injected on MacOS, as we need the
runner to circumvent SIP.
Also add a test that tests the autobuild-action to exercise this code path.

lib/codeql.js

@@ -510,7 +510,13 @@ async function getCodeQLForCmd(cmd, checkVersion) {
                 "-Dhttp.keepAlive=false",
                 "-Dmaven.wagon.http.pool=false",
             ].join(" ");
-            await runTool(autobuildCmd);
+            const runnerExe = process.env["CODEQL_RUNNER"];
+            if (runnerExe) {
+                await runTool(runnerExe, [autobuildCmd]);
+            }
+            else {
+                await runTool(autobuildCmd);
+            }
         },
         async extractScannedLanguage(databasePath, language, featureFlags) {
             // Get extractor location