[foxy backport] Zstd should not install internal headers - some of them try include others that aren't installed. We don't use them. Avoid the situation (#631)

[emersonknapp]

Backport #631 to Foxy

[Karsten1987]

lgtm given the PR build runs through.
I think technically that's already a breaking change (people might link against the installed headers), but I feel confident to let that slip here.

[emersonknapp]

I think technically that's already a breaking change (people might link against the installed headers)

Yes, I think you're right, but I also feel confident that nobody knows about or uses these headers. As far as I can tell - they wouldn't be able to successfully build against them under normal circumstances, because other headers they try to include are not installed.

[emersonknapp]

@ros-pull-request-builder retest this please

[emersonknapp]

The failure is just the API/ABI checker failing on these Zstd headers - I'll merge this and get a Foxy patch build out for rosbag2 in hopes that we can remedy the situation