pin fortawesome from main package.json

(There is a very old package pinned in scripts/, but nothing
ever runs npm ci for that)

Author: osfameron

package-lock.json

@@ -9,6 +9,7 @@
     "@antora/site-generator-ms": "git+https://gitlab.com/opendevise/oss/antora-site-generator-ms#as-extension",
     "@asciidoctor/tabs": "1.0.0-beta.6",
     "@fastify/deepmerge": "^2.0.0",
+    "@fortawesome/free-solid-svg-icons": "^7.1.0",
     "antora": "~3.1",
     "array.prototype.groupby": "^1.1.0",
     "asciidoctor-external-callout": "~1.2.2",