fix(pip): fix file opening encoding

prevent python to automatically choosing the encoding which could lead to UnicodeDecodeError in some cases

src/rez_pip/pip.py

@@ -127,7 +127,7 @@ def getPackages(
  f"{output}",
  )
 
- with open(tmpFile, "r") as fd:
+ with open(tmpFile, "r", encoding="utf-8") as fd:
  rawData = json.load(fd)
  finally:
  os.remove(tmpFile)