Notes for qtwebengine-opensource-src - reproducible builds result

Version annotated: 5.9.1+dfsg-4
Identified issues:
Identifier: captures_build_dir_in_qmake_prl_files
Description QMAKE_PRL_BUILD_DIR contains the absolute build path.
Identifier: blacklisted_on_jenkins_armhf_only
Description Some packages have been blacklisted only on armhf in our test infrastructure
because their builds take too long on the tiny armhf boards we're using.
The mitigation against this is to add more architectures or to wait until
we test against the debian archive, when it will become sensible to raise
the 18h timeout for a single build.
Until his happens, please rely on the amd64, i386 and arm64 tests.

Our notes about issues affecting packages are stored in notes.git and are targeted at packages in Debian in 'unstable/amd64' (unless they say otherwise).