Switch from optional-dependencies to dedicated requirements.txt files

.readthedocs.yaml

@@ -10,7 +10,4 @@ sphinx:
 
 python:
   install:
-    - method: pip
-      path: .
-      extra_requirements:
-        - doc
+    - requirements: docs/requirements.txt

docs/requirements.txt

@@ -0,0 +1,5 @@
+myst-parser
+sphinx-copybutton
+sphinx-design
+sphinx-inline-tabs
+sphinx-tabs

noxfile.py

@@ -66,16 +66,17 @@ def get_release_versions(version_file):
 #
 @nox.session(reuse_venv=True)
 def docs(session):
-    # Generate relevant files prior to installation
-    session.install(".[doc]")
+    session.install("-r", "docs/requirements.txt")
+    session.install(".")
 
     # Generate documentation into `build/docs`
     session.run("sphinx-build", "-b", "dirhtml", "-v", "docs/", "build/docs")
 
 
 @nox.session(name="docs-live", reuse_venv=True)
 def docs_live(session):
-    session.install("-e", ".[doc]", "sphinx-theme-builder[cli]")
+    session.install("-r", "docs/requirements.txt")
+    session.install("-e", ".", "sphinx-theme-builder[cli]")
 
     # Generate documentation into `build/docs`
     session.run("stb", "serve", "docs/")

pyproject.toml

@@ -43,18 +43,5 @@ classifiers = [
   "Topic :: Software Development :: Documentation",
 ]
 
-[project.optional-dependencies]
-test = [
-  "pytest",
-  "pytest-cov",
-  "pytest-xdist",
-]
-doc = [
-  "myst-parser",
-  "sphinx-copybutton",
-  "sphinx-design",
-  "sphinx-inline-tabs",
-]
-
 [project.entry-points]
 "sphinx.html_themes" = {furo = "furo"}