Bug 1749248 - Add missing language names (sco, szl) to MozIntl map, r=platform-i18n-reviewers,dminor

Differential Revision: https://phabricator.services.mozilla.com/D135467

toolkit/components/mozintl/mozIntl.jsm

@@ -732,6 +732,7 @@ const nativeLocaleNames = new Map(
     rm: "Rumantsch",
     ro: "Română",
     ru: "Русский",
+    sco: "Scots",
     si: "සිංහල",
     sk: "Slovenčina",
     sl: "Slovenščina",
@@ -739,6 +740,7 @@ const nativeLocaleNames = new Map(
     sq: "Shqip",
     sr: "Cрпски",
     "sv-SE": "Svenska",
+    szl: "Ślōnsko",
     ta: "தமிழ்",
     te: "తెలుగు",
     th: "ไทย",