Revert fastparquet nullable dtype support
- [ ] closes #xxxx
- [ ] tests added / passed
- [ ] Ensure all linting tests pass, see [here](https://pandas.pydata.org/pandas-docs/dev/development/contributing.html#code-standards) for how to run them
- [ ] whatsnew entry

Hello @lithomas1! Thanks for updating this PR. We checked the lines you've touched for [PEP 8](https://www.python.org/dev/peps/pep-0008) issues, and found:





There are currently no PEP 8 issues detected in this Pull Request. Cheers! :beers: 

##### Comment last updated at 2021-08-10 18:43:10 UTC OK, failing tests are flaky. So this is ready for review now. The backport will be a bit tricky, so I'll do it manually. (Basically backport the last PR and this PR together. We're still gonna backport that one since it unpins fastparquet even though most of its changes are reverted here).

cc @jorisvandenbossche (sorry for not pinging last time) @jreback i am fine with this change. ping for merge @jreback. Just merged master thanks @lithomas1  Owee, I'm MrMeeseeks, Look at me.

There seem to be a conflict, please backport manually. Here are approximate instructions:

1. Checkout backport branch and update it.

```
$ git checkout 1.3.x
$ git pull
```

2. Cherry pick the first parent branch of the this PR on top of the older branch:
```
$ git cherry-pick -m1 45fd72aa1768d2132ab0c294f1cb208d666a8965
```

3. You will likely have some merge/cherry-pick conflict here, fix them and commit:

```
$ git commit -am 'Backport PR #42954: Revert fastparquet nullable dtype support'
```

4. Push to a named branch :

```
git push YOURFORK 1.3.x:auto-backport-of-pr-42954-on-1.3.x
```

5. Create a PR against branch 1.3.x, I would have named this PR:

> "Backport PR #42954 on branch 1.3.x"

And apply the correct labels and milestones.

Congratulation you did some good work ! Hopefully your backport PR will be tested by the continuous integration and merged soon!

If these instruction are inaccurate, feel free to [suggest an improvement](https://github.com/MeeseeksBox/MeeseeksDev).
                 @meeseeksdev backport 1.3.x Owee, I'm MrMeeseeks, Look at me.

There seem to be a conflict, please backport manually. Here are approximate instructions:

1. Checkout backport branch and update it.

```
$ git checkout 1.3.x
$ git pull
```

2. Cherry pick the first parent branch of the this PR on top of the older branch:
```
$ git cherry-pick -m1 45fd72aa1768d2132ab0c294f1cb208d666a8965
```

3. You will likely have some merge/cherry-pick conflict here, fix them and commit:

```
$ git commit -am 'Backport PR #42954: Revert fastparquet nullable dtype support'
```

4. Push to a named branch :

```
git push YOURFORK 1.3.x:auto-backport-of-pr-42954-on-1.3.x
```

5. Create a PR against branch 1.3.x, I would have named this PR:

> "Backport PR #42954 on branch 1.3.x"

And apply the correct labels and milestones.

Congratulation you did some good work ! Hopefully your backport PR will be tested by the continuous integration and merged soon!

If these instruction are inaccurate, feel free to [suggest an improvement](https://github.com/MeeseeksBox/MeeseeksDev).
                 @lithomas1 if you wouldn't mind do the manual backport here > Basically backport the last PR and this PR together.

The net result is no release note. do we need one? It's not clear to me what is changed/fixed? Indeed, no release note, but the two combined PRs still have some changes to support the latest fastparquet version properly (in theory that could have been added as release note). > @lithomas1 if you wouldn't mind do the manual backport here

@lithomas1 what is added and then removed in the release notes is not identical, so have synced the notes in #42985, so no need to backport that change. Sorry, thanks for fixing that, planning on doing the backport now.