worker: bump core version

We are now building against core commit
9b2bb2b691dd7f0a9b69064f0e7449a8958f25fe[1].

This commit is not on core master branch! It is effectively master
commit 9530f384c8331a83bf68782d8daf6f16ee47c2a0 [2] but we had to
remove 1a4de925c48aace75ff364fbc85dc7d8ffac5924 [3] from the tree
because of not yet solved incompatibility (see #76 [4]) and we added a
commit to bump alpine verison to 3.15.

We deploy this because of the feature that allows add documentation not
only to algorithm's overloads but to whole algorithm ([5] in our tree,
[6] in master).

I hope this is an exceptional situation and we get #76 [4] fixed soon so we
don't have to dance around (and manage our core tree) it in the future.

[1]: automata-library@9b2bb2b6
[2]: automata-library@9530f384
[3]: automata-library@1a4de925
[4]: #76
[5]: automata-library@5eac4f8a
[6]: automata-library@3ea71234