Fix OffsetArrays ambiguity resolution again

[yha]

Since JuliaArrays/OffsetArrays.jl#157, OffsetArrays.OffsetAxisKnownLength == Base.DimOrInd, so the ambiguity-resolving method from #1 overwrites the earlier similar method, triggering a warning. This simply removes the method, which is not needed anymore.
For this to work, OffsetArrays needs to be at version >=1.3, so I keep it as a dependency with a comment in Project.toml (comments in Project.toml are not preserved by Pkg operations unfortunately, but I think it's still better than no comment).

[codecov]

Codecov Report

Merging #8 (dfa4db9) into master (2fd9f4b) will increase coverage by 5.26%.
The diff coverage is n/a.

@@             Coverage Diff             @@
##           master        #8      +/-   ##
===========================================
+ Coverage   94.73%   100.00%   +5.26%     
===========================================
  Files           1         1              
  Lines          19        18       -1     
===========================================
  Hits           18        18              
+ Misses          1         0       -1     

Impacted Files	Coverage Δ
src/CircularArrays.jl	100.00% <ø> (+5.26%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 2fd9f4b...dfa4db9. Read the comment docs.

[Vexatos]

This is good news. Isn't it possible to keep the [compat] declaration, but remove the dependency (or change it to tests-only in [extras])? Or would that allow installing it with an outdated version of OffsetArrays?

Edit: Just noticed that removing the dependency entirely while keeping the compat entry does indeed not work, which is unfortunate.

[Vexatos]

I guess I'll have to keep the dependency, at least for now. Will be able to remove it in the future, but this at least resolves #3 partially. Thank you!