remove version comment fixing build issue

[nica-f]

Contribution description

This change resolves a built issue cause by the added comment to the release tag in the Makefile.

Testing procedure

Tested by compiling a project using LVGL.

Issues/PRs references

N/A

[chrysn]

To test, I think you have to have an old checkout of the pkg; trying...

[chrysn]

Testing is highly nontrivial because it only triggers if the relevant hash is not present in the existing checkout -- merely cleaning, going to 2022.04, running the test, going to master and running the test again does not trigger the failure, because if you do that now, then you get a recent checkout and the requested hash is already present.

So, steps to test are (not necessarily minimized):

$ make -C tests/pkg_lvgl
$ cd build/pkg
$ rm -rf lvg
$ git clone https://github.com/littlevgl/lvgl -b fix/img-transform-precision --depth=1
$ cd -
$ make -C tests/pkg_lvgl

Then you get:

fatal: invalid refspec '9024b72b4853e1e7ac29a42e54b7a10d3c4f3b20  '
make[1]: *** [/home/chrysn/git/RIOT/pkg/pkg.mk:125: /home/chrysn/git/RIOT/build/pkg/lvgl/.pkg-state.git-downloaded] Error 128

To quote @nica-f: "Ein schöner corner corner corner case".

The presented patch fixes this.

I suggest that we remove all these comments tree-wide, as that's a very subtle thing to run into.

[kaspar030]

I suggest that we remove all these comments tree-wide, as that's a very subtle thing to run into.

... or move them to another line, they do provide information.

The reasons why we use hashes in the first place are, 1.) git-cache is flakey with tags, and 2.) only hashes ensure immutability.
But IMO 1.) might get fixed and for git tags, we might want to ignore 2.) for friendlyness towards human developers, once git-cache is tested to work poperly with tags. At that point, I'd rather not have to look for the tag names.