json: replaced simplejson with orjson

requirements.txt

@@ -1,53 +1,53 b''
 # deps, generated via pipdeptree --exclude setuptools,wheel,pipdeptree,pip -f | tr '[:upper:]' '[:lower:]'
 
 atomicwrites==1.4.1
 contextlib2==21.6.0
 cov-core==1.15.0
   coverage==7.2.1
 dogpile.cache==1.1.8
   decorator==5.1.1
   stevedore==5.0.0
     pbr==5.11.1
 dulwich==0.21.3
   urllib3==1.26.14
 gunicorn==20.1.0
 hg-evolve==11.0.0
 importlib-metadata==6.0.0
   zipp==3.15.0
 mercurial==6.3.3
 mock==5.0.1
 more-itertools==9.1.0
 msgpack-python==0.5.6
+orjson==3.8.7
 psutil==5.9.4
 py==1.11.0
 pygit2==1.11.1
   cffi==1.15.1
     pycparser==2.21
 pygments==2.14.0
 pyparsing==3.0.9
 pyramid==2.0.1
   hupper==1.11
   plaster==1.1.2
   plaster-pastedeploy==1.0.1
     pastedeploy==3.0.1
     plaster==1.1.2
   translationstring==1.4
   venusian==3.0.0
   webob==1.8.7
   zope.deprecation==4.4.0
   zope.interface==5.5.2
 redis==4.5.1
   async-timeout==4.0.2
 repoze.lru==0.7
 scandir==1.10.0
 setproctitle==1.3.2
-simplejson==3.18.3
 subvertpy==0.11.0
 wcwidth==0.2.6
 
 
 ## test related requirements
 -r requirements_test.txt
 
 ## uncomment to add the debug libraries
 #-r requirements_debug.txt

vcsserver/lib/rc_json.py

@@ -1,1 +1,2 b''
-import simplejson as json
+# use orjson by default
+import orjson as json