CI: Unpin openpyxl

[TomAugspurger]

Followup to #22601 and dask/dask-ml#84 (comment).

Upstream issue: https://bitbucket.org/openpyxl/openpyxl/issues/1094/error-with-pandas-datetimeindex

(one of several in fact filed for this issue)

[gfyoung]

Upstream commit just came in to patch this:

https://bitbucket.org/openpyxl/openpyxl/commits/fa13fbfda13a

Need to wait on next release to unpin this.

[h-vetinari]

Reported error in https://bitbucket.org/openpyxl/openpyxl/issues/1094/error-with-pandas-datetimeindex (thru being duplicate of https://bitbucket.org/openpyxl/openpyxl/issues/1093/newly-introduced-keyerror-problem-in) was fixed in 2.5.7 apparently - current version is 2.5.12. Tagging @alimcmaster1, as he asked about just that on the bitbucket tracker.

[alimcmaster1]

@h-vetinari . I already largely did this #23361 the only build that's that remain pinned are azure-macOS-35, and azure-27-compat build. So I think this is perhaps fine to close unless anyone thinks there is something else we should be doing here?

[gfyoung]

@jreback @TomAugspurger : Do we intend to unpin openpyxl for these two builds?

Otherwise, I do agree that we should close this (and mark for 0.24.0 instead of 0.24.1 in fact).

[jreback]

are we pinning anywhere?

[TomAugspurger]

ci/deps/travis-27.yaml
21:  - openpyxl=2.4.0

ci/deps/azure-27-compat.yaml
11:  - openpyxl=2.5.5

ci/deps/azure-macos-35.yaml
15:  - openpyxl=2.5.5

ci/deps/azure-27-locale.yaml
11:  - openpyxl=2.4.0

We have builds that are not pinned though, so this is probably fine to close. Or some of the ones pinned at 2.5.5 can be lifted, either works for me.

[gfyoung]

The Azure pins I believe were explicitly requested by @jreback when #23361 was merged. Not sure about the Travis one though.

@jreback : Thoughts?

[TomAugspurger]

Closing, since we have a mix of pinned & unpinned.