simplify pyenv startup

.gitlab-ci.yml

@@ -11,16 +11,13 @@ native_Debian_clang:
   before_script: &debian_clang
     - pwd
     - export CC=gcc; export CXX=g++
-    - export PYTHONPATH=$CI_PROJECT_DIR/build/lib
+    - $CC --version
     - export MPLBACKEND=Agg
     - QTCMAKE="/usr/local/Qt6/6.2.3/gcc_64/lib/cmake"
-    - export PYENV_ROOT="$HOME/.pyenv"
-    - command -v pyenv >/dev/null || export PATH="$PYENV_ROOT/bin:$PATH"
+    - pyenv version
+    - export PATH="$HOME/.pyenv/bin:$PATH"
     - eval "$(pyenv init -)"
-    - which python
-    - python --version
     - cmake --version
-    - clang --version
   stage: build
   script: &native_scr
     - env