transition: lazy-regex 2 -> 3

Versions of rust-lazy-regex in unstable:
  librust-lazy-regex-dev                           2.5.0-3

Versions of rdeps of rust-lazy-regex in unstable, that also exist in testing:
  librust-breezyshim-dev                           0.1.204-1        depends on     librust-lazy-regex+default-dev (>= 2-~~),
  librust-debbugs-dev                              0.1.1-1+b2       depends on     librust-lazy-regex+default-dev (>= 2.5-~~),
  librust-debian-analyzer-dev                      0.158.18-1       depends on     librust-lazy-regex+default-dev (>= 2-~~),
  librust-debian-changelog-dev                     0.1.14-1         depends on     librust-lazy-regex+default-dev (>= 2-~~),
  librust-debversion-dev                           0.4.3-2          depends on     librust-lazy-regex+default-dev (>= 2-~~),
  librust-lfs-core-dev                             0.11.2-1         depends on     librust-lazy-regex-2+default-dev (>= 2.5-~~),
  librust-patchkit-dev                             0.1.8-2          depends on     librust-lazy-regex+default-dev (>= 2-~~),
  librust-pinger-dev                               1.2.3-1          depends on     librust-lazy-regex+default-dev (>= 2.5-~~),
  librust-termimad-dev                             0.29.4-1         depends on     librust-lazy-regex+default-dev (>= 2.5-~~),