ci: use default Python settings for cmake

.github/workflows/ccpp.yml

@@ -34,7 +34,7 @@ jobs:
         export MAKEFLAGS="-j2"
         mkdir build
         cd build
-        cmake .. -DCMAKE_BUILD_TYPE=Debug -DBUILD_WITH_COLLISION_SUPPORT=ON -DPYTHON_EXECUTABLE=$(which python2) -DBUILD_ADVANCED_TESTING=ON
+        cmake .. -DCMAKE_BUILD_TYPE=Debug -DBUILD_WITH_COLLISION_SUPPORT=ON -DBUILD_ADVANCED_TESTING=ON
         make
         make build_tests
         export CTEST_OUTPUT_ON_FAILURE=1

travis_custom/custom_build

@@ -5,13 +5,6 @@ set -e
 set -x
 set -v
 
-# Setup environment variables.
-if [[ $TRAVIS_PYTHON_VERSION -gt 30 ]]; then
-  export CMAKE_ADDITIONAL_OPTIONS=" ${CMAKE_ADDITIONAL_OPTIONS} -DPYTHON_EXECUTABLE=$(which python3)"
-else
-  export CMAKE_ADDITIONAL_OPTIONS=" ${CMAKE_ADDITIONAL_OPTIONS} -DPYTHON_EXECUTABLE=$(which python2)"
-fi
-
 export CMAKE_ADDITIONAL_OPTIONS=" ${CMAKE_ADDITIONAL_OPTIONS} -DBUILD_BENCHMARK=\"ON\" -DBUILD_TESTING=\"ON\" -DCMAKE_CXX_FLAGS=-DBOOST_SYSTEM_NO_DEPRECATED"
 if [[ ";${DO_INSTALL_DOC_EXCEPT_ON_BRANCH};" == *";${CI_BRANCH};"* ]]; then
   export CMAKE_ADDITIONAL_OPTIONS=" ${CMAKE_ADDITIONAL_OPTIONS} -DINSTALL_DOCUMENTATION=\"OFF\""