deps: replace deprecated ujson with orjson

UJSON is deprecated and no longer recommended. Replace with orjson,
which is the recommended alternative.

Changes:
- pyproject.toml: update dependency from ujson to orjson
- pylsp/__main__.py: import orjson instead of ujson
- pylsp/plugins/pylint_lint.py: import orjson instead of ujson
- pylsp/python_lsp.py: import orjson instead of ujson

Fixes #673

Author: Leo Ji

pylsp/__main__.py

@@ -8,7 +8,7 @@
 import time
 
 try:
-    import ujson as json
+    import orjson as json
 except Exception:
     import json
 

pylsp/plugins/pylint_lint.py

@@ -15,7 +15,7 @@
 from pylsp import hookimpl, lsp
 
 try:
-    import ujson as json
+    import orjson as json
 except Exception:
     import json
 

pylsp/python_lsp.py

@@ -11,7 +11,7 @@
 from typing import Any
 
 try:
-    import ujson as json
+    import orjson as json
 except Exception:
     import json
 

pyproject.toml

@@ -19,7 +19,7 @@ dependencies = [
     "jedi>=0.17.2,<0.20.0",
     "pluggy>=1.0.0",
     "python-lsp-jsonrpc>=1.1.0,<2.0.0",
-    "ujson>=3.0.0",
+    "orjson>=3.0.0",
     "black"
 ]
 dynamic = ["version"]