devel/bazel: Update to 3.6.0
Minor release with several bug fixes and some incompatible changes[1].
[1] https://blog.bazel.build/2020/10/06/bazel-3-6.html
Renewed almost all patches under files/ (via make makepatch).
PR: 250164
Submitted by: Klaus Aehlig <aehlig@linta.de> (maintainer)
Approved by: arrowd (mentor)
Differential Revision: https://reviews.freebsd.org/D26715