Drop Python 2 support

IMP has dropped Python 2 suppport, so we must too.

.github/workflows/build.yml

@@ -13,11 +13,11 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest]
-        python-version: ["2.7", "3.12"]
+        python-version: ["3.12"]
     runs-on: ${{ matrix.os }}
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v4
       with:
         submodules: true
     - name: Setup conda
@@ -31,8 +31,7 @@ jobs:
         source ${CONDA_PREFIX}/etc/conda/activate.d/activate-gcc_linux-64.sh
         source ${CONDA_PREFIX}/etc/conda/activate.d/activate-gxx_linux-64.sh
         mkdir build && cd build
-        if test "${{ matrix.python-version }}" = "2.7" ; then PY2=on; else PY2=off; fi
-        cmake .. -DIMP_DIR=${CONDA_PREFIX}/lib/cmake/IMP -DUSE_PYTHON2=${PY2} -DCMAKE_CXX_FLAGS="-fprofile-arcs -ftest-coverage"
+        cmake .. -DIMP_DIR=${CONDA_PREFIX}/lib/cmake/IMP -DCMAKE_CXX_FLAGS="-fprofile-arcs -ftest-coverage"
         make
         ./setup_environment.sh pytest --cov=.. --cov-branch --cov-report=xml -v test/*/*.py
         ${GCC/gcc/gcov} $(find . -name "*.gcno")

tools/setup_ci.sh

@@ -9,18 +9,8 @@ fi
 
 python_version=$1
 
-if [ ${python_version} = "2.7" ]; then
-  BOOST=""
-  pip="pip<=19.3.1"
-  # Python.h includes crypt.h, which is no longer provided by default
-  crypt="libxcrypt"
-else
-  BOOST="libboost-devel"
-  pip="pip"
-  crypt=""
-fi
 conda config --remove channels defaults  # get conda-forge, not main, packages
-conda create --yes -q -n python${python_version} -c salilab -c conda-forge python=${python_version} ${pip} ${crypt} imp-nightly ${BOOST} gxx_linux-64 eigen cereal swig cmake numpy
+conda create --yes -q -n python${python_version} -c salilab -c conda-forge python=${python_version} pip imp-nightly libboost-devel gxx_linux-64 eigen cereal swig cmake numpy
 eval "$(conda shell.bash hook)"
 conda activate python${python_version}
 pip install pytest-cov coverage