* gnu/packages/patches/scons-test-environment.patch: New file.
* gnu/local.mk (dist_patch_DATA): Adjust accordingly.
* gnu/packages/build-tools.scm (scons): Update to 4.4.0.
[source](patches): New field.
[arguments]: Adjust bootstrap for the new version. Enable tests.
[native-inputs]: Add PYTHON-WHEEL and PYTHON-PSUTIL.
(scons-3): New variable.
(scons-python2): Inherit from it.
* gnu/packages/web.scm (serf)[arguments]: Stick with SCONS-3 to prevent rebuilds.
