fix exporting env vars on linux

lib/runner.js

@@ -103,7 +103,8 @@ program
                 // Assume that anything that's not windows is using a unix-style shell
                 const envFile = path.join(config.tempDir, 'codeql-env.sh');
                 const envFileContents = Object.entries(tracerConfig.env)
-                    .map(([key, value]) => `${key}="${value}"`)
+                    // Some vars contain ${LIB} that we do not want to be expanded when executing this script
+                    .map(([key, value]) => `export ${key}="${value.replace('$', '\\$')}"`)
                     .join('\n');
                 fs.writeFileSync(envFile, envFileContents);
                 logger.info(`\nCodeQL environment outputted to "${envFile}". ` +