Switch docs dependencies to a dependency group

Author: notatallshaw

docs/requirements.txt

@@ -24,9 +24,6 @@
     "common-wheels": "tests/data/common_wheels",
     "protected-pip": "tools/protected_pip.py",
 }
-REQUIREMENTS = {
-    "docs": "docs/requirements.txt",
-}
 
 AUTHORS_FILE = "AUTHORS.txt"
 VERSION_FILE = "src/pip/__init__.py"
@@ -132,7 +129,7 @@ def test(session: nox.Session) -> None:
 
 @nox.session
 def docs(session: nox.Session) -> None:
-    session.install("-r", REQUIREMENTS["docs"])
+    session.install("--group", "docs")
 
     def get_sphinx_build_command(kind: str) -> list[str]:
         # Having the conf.py in the docs/html is weird but needed because we
@@ -161,7 +158,7 @@ def get_sphinx_build_command(kind: str) -> list[str]:
 
 @nox.session(name="docs-live")
 def docs_live(session: nox.Session) -> None:
-    session.install("-r", REQUIREMENTS["docs"], "sphinx-autobuild")
+    session.install("--group", "docs", "sphinx-autobuild")
 
     session.run(
         "sphinx-autobuild",
@@ -267,7 +264,7 @@ def coverage(session: nox.Session) -> None:
     run_with_protected_pip(session, "install", ".")
 
     # Install test dependencies
-    run_with_protected_pip(session, "install", "-r", REQUIREMENTS["tests"])
+    run_with_protected_pip(session, "install", "--group", "tests")
 
     if not os.path.exists(".coverage-output"):
         os.mkdir(".coverage-output")

noxfile.py

@@ -83,6 +83,19 @@ test-common-wheels = [
     "pytest-subket >= 0.8.1",
 ]
 
+docs = [
+    "sphinx ~= 7.0",
+    # currently incompatible with sphinxcontrib-towncrier
+    # https://github.com/sphinx-contrib/sphinxcontrib-towncrier/issues/92
+    "towncrier < 24",
+    "furo",
+    "myst_parser",
+    "sphinx-copybutton",
+    "sphinx-inline-tabs",
+    "sphinxcontrib-towncrier >= 0.2.0a0",
+    "sphinx-issues",
+]
+
 [tool.flit.sdist]
 include = [
     "NEWS.rst",