Fix typo in extract-mitre-attacks script

We were backgrounding the process (&) instead of ANDing it with the
linting. Whoops!

x-pack/plugins/siem/package.json

@@ -5,7 +5,7 @@
   "private": true,
   "license": "Elastic-License",
   "scripts": {
-    "extract-mitre-attacks": "node scripts/extract_tactics_techniques_mitre.js & node ../../../scripts/eslint ../../legacy/plugins/siem/public/pages/detection_engine/mitre/mitre_tactics_techniques.ts --fix",
+    "extract-mitre-attacks": "node scripts/extract_tactics_techniques_mitre.js && node ../../../scripts/eslint ../../legacy/plugins/siem/public/pages/detection_engine/mitre/mitre_tactics_techniques.ts --fix",
     "build-graphql-types": "node scripts/generate_types_from_graphql.js",
     "cypress:open": "cypress open --config-file ./cypress/cypress.json",
     "cypress:run": "cypress run --spec ./cypress/integration/**/*.spec.ts --config-file ./cypress/cypress.json --reporter ../../node_modules/cypress-multi-reporters --reporter-options configFile=./cypress/reporter_config.json; status=$?; ../../node_modules/.bin/mochawesome-merge --reportDir ../../../target/kibana-siem/cypress/results > ../../../target/kibana-siem/cypress/results/output.json; ../../../node_modules/.bin/marge ../../../target/kibana-siem/cypress/results/output.json --reportDir ../../../target/kibana-siem/cypress/results; mkdir -p ../../../target/junit && cp ../../../target/kibana-siem/cypress/results/*.xml ../../../target/junit/ && exit $status;",