Use system python for github actions CI

Signed-off-by: Alex Forencich <alex@alexforencich.com>

.github/workflows/regression-tests.yml

@@ -9,18 +9,12 @@ jobs:
     
     strategy:
       matrix:
-        python-version: ["3.13"]
         # group: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
         group: [1]
 
     steps:
     - uses: actions/checkout@v3
 
-    - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@v4
-      with:
-        python-version: ${{ matrix.python-version }}
-
     - name: Install Ubuntu packages
       run: |
         sudo apt install -y --no-install-recommends iverilog verilator

tox.ini

@@ -5,10 +5,6 @@ skipsdist = True
 minversion = 3.2.0
 requires = virtualenv >= 16.1
 
-[gh-actions]
-python =
-    3.13: py3
-
 [testenv]
 deps =
     pytest == 8.3.4