Add support for Python 3.11 (#33505)

Argparse started raising ArgumentError exceptions
when the same parser is added twice. Therefore, we
perform the addition only if the parser is not there
already

Port match syntax to our unparser

.github/workflows/unit_tests.yaml

@@ -14,7 +14,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ['2.7', '3.6', '3.7', '3.8', '3.9', '3.10']
+        python-version: ['2.7', '3.6', '3.7', '3.8', '3.9', '3.10', '3.11']
         concretizer: ['clingo']
         on_develop:
         - ${{ github.ref == 'refs/heads/develop' }}
@@ -22,7 +22,7 @@ jobs:
         - python-version: 2.7
           concretizer: original
           on_develop: ${{ github.ref == 'refs/heads/develop' }}
-        - python-version: '3.10'
+        - python-version: '3.11'
           concretizer: original
           on_develop: ${{ github.ref == 'refs/heads/develop' }}
         exclude:
@@ -35,6 +35,9 @@ jobs:
         - python-version: '3.9'
           concretizer: 'clingo'
           on_develop: false
+        - python-version: '3.10'
+          concretizer: 'clingo'
+          on_develop: false
 
     steps:
     - uses: actions/checkout@93ea575cb5d8a053eaa0ac8fa3b40d7e05a33cc8 # @v2
@@ -86,7 +89,7 @@ jobs:
           SPACK_TEST_SOLVER: ${{ matrix.concretizer }}
           SPACK_TEST_PARALLEL: 2
           COVERAGE: true
-          UNIT_TEST_COVERAGE: ${{ (matrix.python-version == '3.10') }}
+          UNIT_TEST_COVERAGE: ${{ (matrix.python-version == '3.11') }}
       run: |
           share/spack/qa/run-unit-tests
     - uses: codecov/codecov-action@d9f34f8cd5cb3b3eb79b3e4b5dae3a16df499a70
@@ -101,7 +104,7 @@ jobs:
         fetch-depth: 0
     - uses: actions/setup-python@13ae5bb136fac2878aff31522b9efb785519f984 # @v2
       with:
-        python-version: '3.10'
+        python-version: '3.11'
     - name: Install System packages
       run: |
           sudo apt-get -y update
@@ -109,7 +112,7 @@ jobs:
           sudo apt-get install -y coreutils kcov csh zsh tcsh fish dash bash
     - name: Install Python packages
       run: |
-          pip install --upgrade pip six setuptools pytest codecov coverage[toml]==6.2 pytest-xdist
+          pip install --upgrade pip six setuptools pytest codecov coverage[toml] pytest-xdist
     - name: Setup git configuration
       run: |
           # Need this for the git tests to succeed.
@@ -158,7 +161,7 @@ jobs:
         fetch-depth: 0
     - uses: actions/setup-python@13ae5bb136fac2878aff31522b9efb785519f984 # @v2
       with:
-        python-version: '3.10'
+        python-version: '3.11'
     - name: Install System packages
       run: |
           sudo apt-get -y update