Strip RPATH from installed Ogre binaries.

[hidmic]

Ogre installs RPATHs by default. Since rviz_ogre_vendor builds and installs Ogre within the build tree first, we wind up with binaries in the install tree that refer to the build tree e.g.:

$ readelf -d /opt/ros/rolling/opt/rviz_ogre_vendor/lib/OGRE/Plugin_OctreeZone.so

Dynamic section at offset 0xdd70 contains 31 entries:
  Tag        Type                         Name/Value
 0x0000000000000001 (NEEDED)             Shared library: [Plugin_PCZSceneManager.so.1.12.1]
 0x0000000000000001 (NEEDED)             Shared library: [libOgreMain.so.1.12.1]
 0x0000000000000001 (NEEDED)             Shared library: [libstdc++.so.6]
 0x0000000000000001 (NEEDED)             Shared library: [libm.so.6]
 0x0000000000000001 (NEEDED)             Shared library: [libgcc_s.so.1]
 0x0000000000000001 (NEEDED)             Shared library: [libc.so.6]
 0x000000000000000e (SONAME)             Library soname: [Plugin_OctreeZone.so.1.12.1]
 0x000000000000001d (RUNPATH)            Library runpath: [/tmp/binarydeb/ros-rolling-rviz-ogre-vendor-8.5.0/obj-x86_64-linux-gnu/ogre_install/lib:/tmp/binarydeb/ros-rolling-rviz-ogre-vendor-8.5.0/obj-x86_64-linux-gnu/ogre_install/lib/OGRE]
...

This patch fixes this by stripping RPATHs entirely.

[hidmic]

CI up to rviz_ogre_vendor, rviz_rendering, rviz_rendering_tests, rviz_default_plugins, rviz_common:

• Linux
• Linux-aarch64
• macOS
• Windows

[clalancette]

I think this PR broke builds on the buildfarm: https://build.ros2.org/view/Rbin_uF64/job/Rbin_uF64__rviz_ogre_vendor__ubuntu_focal_amd64__binary/34/console has been failing since 8.6.0 was released into Rolling.

[hidmic]

It seems dh_shlibdeps is now complaining about missing dependencies. This was the only package that had RPATHs, so I don't yet understand what's special about it.