Revert "Migrated test dependencies to dependency groups"

No version of pip available on Python 3.8 supports dependency groups.

Author: agronholm

.github/workflows/test.yml

@@ -46,10 +46,8 @@ jobs:
         allow-prereleases: true
         cache: pip
         cache-dependency-path: pyproject.toml
-    - name: Ensure pip >= v25.1
-      run: python -m pip install "pip >= 25.1"
-    - name: Install the project and its dependencies
-      run: pip install --group test -e .
+    - name: Install dependencies
+      run: pip install -e .[test] coverage
     - name: Test with pytest
       run: coverage run -m pytest
     - name: Upload Coverage

pyproject.toml

@@ -27,9 +27,8 @@ Changelog = "https://github.com/agronholm/exceptiongroup/blob/main/CHANGES.rst"
 "Source code" = "https://github.com/agronholm/exceptiongroup"
 "Issue Tracker" = "https://github.com/agronholm/exceptiongroup/issues"
 
-[dependency-groups]
+[project.optional-dependencies]
 test = [
-    "coverage",
     "pytest >= 6"
 ]
 
@@ -97,7 +96,7 @@ requires = ["tox >= 4.22"]
 [tool.tox.env_run_base]
 commands = [["python", "-m", "pytest", { replace = "posargs", extend = true }]]
 package = "editable"
-dependency_groups = ["test"]
+extras = ["test"]
 
 [tool.tox.env.typing]
 commands = [