Update to Python 3.12

* Remove toml dependency since that comes with Python as of 3.11
* Update toml usage to tomllib in config.py
* Update `with open(...)` for toml file reading to be 'rb'
* Update Pipfile.lock for locked dependencies to work with Python 3.12

Signed-off-by: Alek Ratzloff <alekratz@gmail.com>

Pipfile

@@ -5,7 +5,6 @@ name = "pypi"
 
 [packages]
 async-irc = "*"
-toml = {version="*", markers="python_version < '3.11'"}
 types-toml = "*"
 "aiohttp[speedups]" = "*"
 async-timeout = ">=4"
@@ -15,7 +14,7 @@ mypy = "*"
 black = "*"
 
 [requires]
-python_version = "3.10"
+python_version = "3.12"
 
 [pipenv]
 allow_prereleases = true