Devops: Fix the test-install.yml workflow (#6409)

* The `uses` key requires full relative path when using a local path
  to include, i.e., the leading `./` is required in the following:
   
      used: `./.github/actions/install-aiida-core

* The action `upload-artifact@v4` no longer supports uploading multiple
  files with the same name, so they now include the Python version.

* The Sphinx extension test is made more robust by making it insensitive
  to the version of docutils used.

.github/workflows/test-install.yml

@@ -216,10 +216,10 @@ jobs:
       run: sudo apt update && sudo apt install postgresql graphviz
 
     - name: Install aiida-core
-      uses: .github/actions/install-aiida-core
+      uses: ./.github/actions/install-aiida-core
       with:
         python-version: ${{ matrix.python-version }}
-        extras: '[atomic_tools, docs, notebook, rest, tests, tui]'
+        extras: '[atomic_tools,docs,notebook,rest,tests,tui]'
         from-requirements: 'false'
 
     - name: Setup AiiDA environment
@@ -239,7 +239,7 @@ jobs:
     # updating the requirements (in case they are  inconsistent with the pyproject.toml file).
     - uses: actions/upload-artifact@v4
       with:
-        name: requirements.txt
+        name: requirements-py-${{ matrix.python-version }}.txt
         path: requirements-py-${{ matrix.python-version }}.txt
 
 # Check whether the requirements/ files are consistent with the dependency specification in the pyproject.toml file.
@@ -293,7 +293,8 @@ jobs:
       if: steps.check_reqs.outcome == 'Failure'  # only run if requirements/ are inconsistent
       uses: actions/download-artifact@v4
       with:
-        name: requirements.txt
+        pattern: requirements-py-*
+        merge-multiple: true
         path: requirements
 
     - name: Commit requirements files

tests/sphinxext/test_workchain.py

@@ -24,6 +24,7 @@ def test_workchain_build(sphinx_build_factory, file_regression):
     # Need to remove the ``source`` attribute of the ``document`` tag as that is variable.
     output = (sphinx_build.outdir / 'index.xml').read_text()
     output = re.sub(r'source=".*"', '', output)
+    output = re.sub(r'<!-- Generated by Docutils.*-->', '<!-- Generated by Docutils -->', output)
 
     file_regression.check(output, encoding='utf-8', extension='.xml')
 

tests/sphinxext/test_workchain/test_workchain_build.xml

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <!DOCTYPE document PUBLIC "+//IDN docutils.sourceforge.net//DTD Docutils Generic//EN//XML" "http://docutils.sourceforge.net/docs/ref/docutils.dtd">
-<!-- Generated by Docutils 0.20.1 -->
+<!-- Generated by Docutils -->
 <document >
     <section ids="sphinx-aiida-demo" names="sphinx-aiida\ demo">
         <title>sphinx-aiida demo</title>