Address PR comments

Author: fpseverino

package.json

@@ -2019,7 +2019,7 @@
     "soundness": "scripts/soundness.sh",
     "check-package-json": "tsx ./scripts/check_package_json.ts",
     "test": "vscode-test && npm run grammar-test",
-    "grammar-test": "vscode-tmgrammar-test \"test/unit-tests/**/*.test.swift.gyb\" -g test/unit-tests/syntaxes/swift.tmLanguage.json -g test/unit-tests/syntaxes/MagicPython.tmLanguage.json",
+    "grammar-test": "vscode-tmgrammar-test test/unit-tests/**/*.test.swift.gyb -g test/unit-tests/syntaxes/swift.tmLanguage.json -g test/unit-tests/syntaxes/MagicPython.tmLanguage.json",
     "integration-test": "npm test -- --label integrationTests",
     "unit-test": "npm test -- --label unitTests",
     "coverage": "npm test -- --coverage",

syntaxes/swift-gyb.tmLanguage.json

@@ -25,7 +25,7 @@
     },
     "gyb-start-control-statement": {
       "name": "meta.embedded.control.begin.gyb",
-      "begin": "^\\s*(%)(?!\\{|\\s*end\\b).+?",
+      "begin": "^\\s*(%)(?!\\{|\\s*end\\b)",
       "beginCaptures": {
         "1": { "name": "keyword.control.flow.gyb" }
       },