Auto-format pyproject.toml with pyproject-fmt tool

Extracted from #201 to make a
cleaner diff.

References:

* https://pyproject-fmt.readthedocs.io/en/latest/

.pre-commit-config.yaml

@@ -53,3 +53,9 @@ repos:
     rev: "1.16.0"
     hooks:
       - id: blacken-docs
+
+  - repo: https://github.com/tox-dev/pyproject-fmt
+    rev: "1.5.3"
+    hooks:
+      - id: pyproject-fmt
+        args: [--indent, "4"]

pyproject.toml

@@ -1,22 +1,29 @@
 [build-system]
-requires = ["flit_core >=3.2.0,<4"]
 build-backend = "flit_core.buildapi"
+requires = [
+    "flit_core<4,>=3.2",
+]
 
 [project]
 name = "installer"
+readme = "README.md"
 authors = [
     { name = "Pradyun Gedam", email = "[email protected]" },
 ]
-readme = "README.md"
+requires-python = ">=3.8"
 classifiers = [
     "License :: OSI Approved :: MIT License",
+    "Programming Language :: Python :: 3 :: Only",
+    "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",
 ]
-requires-python = ">=3.8"
 dynamic = [
-    "version",
     "description",
+    "version",
 ]
-
 [project.urls]
 "GitHub" = "https://github.com/pypa/installer"