Make it build and delete some files not needed for purpose.

CURA-12568

Author: rburema

conanfile.py

@@ -582,7 +582,7 @@ def _make_internal_distinct(self):
                     continue
                 with theme_path.open("r") as theme_file:
                     theme = json.load(theme_file)
-                    if theme["colors"]:
+                    if "colors" in theme:
                         theme["colors"]["main_window_header_background"] = test_colors[biweekly_day]
                 with theme_path.open("w") as theme_file:
                     json.dump(theme, theme_file)

resources/bundled_packages/cura.json

@@ -16,23 +16,6 @@
             }
         }
     },
-    "BlackBeltPlugin": {
-        "package_info": {
-            "package_id": "BlackBeltPlugin",
-            "package_type": "plugin",
-            "display_name": "BlackBelt plugin",
-            "description": "Adds support for BlackBelt and other printers with slanted gantries.",
-            "package_version": "3.6.0",
-            "sdk_version": 5,
-            "website": "https://blackbelt-3d.com",
-            "author": {
-                "author_id": "Blackbelt3d",
-                "display_name": "BLACKBELT 3D",
-                "email": "[email protected]",
-                "website": "https://blackbelt-3d.com"
-            }
-        }
-    },
     "3MFReader": {
         "package_info": {
             "package_id": "3MFReader",