fix(language): replace oe with œ where relevant (@bersace) (monkeytypegame#7130)

### Description

Fix more ligatures on French.

Supersedes monkeytypegame#7111 

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Author: bersace

frontend/static/languages/french_1k.json

@@ -228,7 +228,7 @@
     "claire",
     "classe",
     "clef",
-    "coeur",
+    "cœur",
     "coin",
     "colère",
     "colline",
@@ -851,8 +851,8 @@
     "occasion",
     "occuper",
     "odeur",
-    "oeil",
-    "oeuvre",
+    "œil",
+    "œuvre",
     "officier",
     "offrir",
     "oh",

frontend/static/languages/french_2k.json

@@ -230,7 +230,7 @@
     "claire",
     "classe",
     "clef",
-    "coeur",
+    "cœur",
     "coin",
     "colère",
     "colline",
@@ -859,8 +859,8 @@
     "occasion",
     "occuper",
     "odeur",
-    "oeil",
-    "oeuvre",
+    "œil",
+    "œuvre",
     "officier",
     "offrir",
     "oh",