Remove unnecessary production dependencies

- pytest (reason: moved to requirements-dev.txt)
- py (reasons: maintenance mode, unused)
- attrs (reason: unused)
- pluggy (reason: moved to requirements-dev.txt)
- iniconfig (reason: moved to requirements-dev.txt)
- black (reason: moved to requirements-dev.txt)
- jwcrypto 1.5 -> 1.5.6 (reason: improved security)
- python_jwt -> pyjwt (reason: deprecated)
- six (reason: unused, also Python 2 support got dropped long ago)

requirements.txt

@@ -1,12 +1,4 @@
-pytest~=8.1.1
-py~=1.11.0
-attrs~=23.2.0
-pluggy~=1.4.0
-iniconfig~=2.0.0
-requests~=2.31.0
-black~=24.3
 colorama~=0.4.6
-
-jwcrypto~=1.5
-python_jwt~=4.1
-six~=1.16
+jwcrypto~=1.5.6
+pyjwt~=2.8.0
+requests~=2.31.0

setup.cfg

@@ -16,13 +16,12 @@ license = MIT License
 [options]
 packages = timewsync
 install_requires =
-  requests
-  jwcrypto
-  python_jwt
-  six
   colorama
+  jwcrypto
+  pyjwt
+  requests
   importlib; python_version == "2.6"
-python_requires = >=3.7
+python_requires = >=3.8
 
 [options.entry_points]
 console_scripts =