Bumped gscan to 4.0.0-pre.4

refs https://github.com/TryGhost/Team/issues/492

- updates regex that checks valid files to test rules against to include all *.hbs files
- cleans up rules for last4 and currency_symbol helpers

package.json

@@ -96,7 +96,7 @@
     "ghost-storage-base": "0.0.4",
     "glob": "7.1.6",
     "got": "9.6.0",
-    "gscan": "4.0.0-pre.2",
+    "gscan": "4.0.0-pre.4",
     "html-to-text": "5.1.1",
     "image-size": "0.8.3",
     "intl": "1.2.5",

yarn.lock

@@ -4453,10 +4453,10 @@ grunt@1.3.0:
     nopt "~3.0.6"
     rimraf "~3.0.2"
 
-gscan@4.0.0-pre.2:
-  version "4.0.0-pre.2"
-  resolved "https://registry.yarnpkg.com/gscan/-/gscan-4.0.0-pre.2.tgz#f8962047d7fcd0edd7f201efefc655338ad9208a"
-  integrity sha512-+pCApO1vd8f6oV7xkuv3Qp3Ofgyi+VPVHzbVb3vhh5z6cvq0BgiLl+Z1kNCdjW9ODwcutZRBLV34iBji63B0kg==
+gscan@4.0.0-pre.4:
+  version "4.0.0-pre.4"
+  resolved "https://registry.npmjs.org/gscan/-/gscan-4.0.0-pre.4.tgz#b036dde2377c57f28c6574708fd3733d7524346a"
+  integrity sha512-QtDQkKDYYbOy0UqvtiFI/8WG0Hi2CbQl8MipDPHEv3K0c3QZLrWrrsTBSJs6dc9a+2TM6isXbSIVF1KDCbSTdA==
   dependencies:
     "@sentry/node" "6.2.1"
     "@tryghost/pretty-cli" "1.2.15"