fabric: version-lock fabric.mod.json

This is intended to reduce user errors where e.g. someone uses the
1.19 jar on 1.19.2. Previously this would lead to unspecific mixin
errors; with this change, a helpful message is shown:

Mod 'Dynmap' (dynmap) 3.4-SNAPSHOT requires version 1.19 of 'Minecraft' (minecraft), but only the wrong version is present: 1.19.2!

fabric-1.18.2/src/main/resources/fabric.mod.json

@@ -28,6 +28,6 @@
   "depends": {
     "fabricloader": ">=0.13.3",
     "fabric": ">=0.47.8",
-    "minecraft": ">=1.18.2"
+    "minecraft": "1.18.2"
   }
 }