Improve the way we depend on IPython and IPykernel per Python version

That will allow us to handle those dependencies better for Python 3.8+

requirements/posix.txt

@@ -1,6 +1,6 @@
 cloudpickle
 ipykernel>=6.23.2,<7
-ipython>=7.31.1,<9
+ipython>=8.12.2,<9
 jupyter_client>=7.4.9,<9
 pyzmq>=22.1.0
 wurlitzer>=1.0.3

requirements/windows.txt

@@ -1,5 +1,5 @@
 cloudpickle
 ipykernel>=6.23.2,<7
-ipython>=7.31.1,<9
+ipython>=8.12.2,<9
 jupyter_client>=7.4.9,<9
 pyzmq>=22.1.0

setup.py

@@ -40,9 +40,12 @@ def get_version(module='spyder_kernels'):
     'backports.functools-lru-cache; python_version<"3"',
     'cloudpickle',
     'ipykernel>=4.5,<5; python_version<"3"',
-    'ipykernel>=6.23.2,<7; python_version>="3"',
+    'ipykernel>=6.16.1,<6.17; python_version<"3.8"',
+    'ipykernel>=6.23.2,<7; python_version>="3.8"',
     'ipython<6; python_version<"3"',
-    'ipython>=7.31.1,<9,!=8.8.0,!=8.9.0,!=8.10.0,!=8.11.0,!=8.12.0,!=8.12.1; python_version>="3"',
+    'ipython>=7.31.1,<8; python_version<"3.8"',
+    'ipython>=8.12.2,<8.13; python_version=="3.8"',
+    'ipython>=8.13.0,<9; python_version>="3.8"',
     'jupyter-client>=5.3.4,<6; python_version<"3"',
     'jupyter-client>=7.4.9,<9; python_version>="3"',
     'pyzmq>=17,<20; python_version<"3"',
@@ -92,10 +95,12 @@ def get_version(module='spyder_kernels'):
         'Programming Language :: Python :: 2',
         'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',
         'Programming Language :: Python :: 3.8',
         'Programming Language :: Python :: 3.9',
+        'Programming Language :: Python :: 3.10',
+        'Programming Language :: Python :: 3.11',
+        'Programming Language :: Python :: 3.12',
         'Topic :: Software Development :: Interpreters',
     ]
 )