[cmake] OGS_USE_PIP defaults to OFF!

CMakeLists.txt

CMakePresets.json

scripts/ci/jobs/build-docs.yml

scripts/ci/jobs/build-linux-frontend.yml

scripts/ci/jobs/build-linux-petsc.yml

scripts/ci/jobs/build-linux.yml

scripts/ci/jobs/build-mac.yml

scripts/ci/jobs/build-win.yml

scripts/ci/jobs/check-header.yml

scripts/ci/jobs/code-coverage.yml

scripts/ci/jobs/package.yml

scripts/cmake/PythonSetup.cmake

scripts/cmake/test/AddTest.cmake

...tent/docs/devguide/getting-started/build-configuration.md