ENH: Add all released Python version above 3.8 to CI

Add all released Python version above 3.8 to CI: WMA is known to work
with Python 3.10, so add this and other versions so that there can be an
indication that the tool can be used with such versions.

.github/workflows/test_package.yaml

@@ -11,7 +11,7 @@ jobs:
       # max-parallel: 6
       matrix:
         os: [ubuntu-latest]
-        python-version: ['3.8']
+        python-version: ['3.8', '3.9', '3.10', '3.11']
 
     steps:
     - name: Check out repository

requirements.txt

@@ -1,12 +1,15 @@
 joblib==1.1.*
 matplotlib==3.6.*
 nibabel==3.0.*
-numpy==1.20.*
+numpy==1.20.*;python_version=="3.8"
+numpy==1.21.*;python_version=="3.9"
 pandas==2.0.3
 pytest
 pytest_console_scripts
 setuptools==44.0.*
-scipy==1.4.*
-statsmodels==0.10.*
+scipy==1.4.*;python_version=="3.8"
+scipy==1.5.*;python_version=="3.9"
+statsmodels==0.10.*;python_version=="3.8"
+statsmodels==0.13.*;python_version=="3.9"
 vtk==9.1.*
 xlrd