CI: Set max job limit for test runs
xref https://github.com/pandas-dev/pandas/pull/45946

If a test run goes beyond 1.5/2 hours, I think it's safe to assume that the test run had an issue. (Since GHA will run for 6 hours, better to short circuit at 2 hours)

@meeseeksdev backport 1.4.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 1.4.x
git pull
```

2. Cherry pick the first parent branch of the this PR on top of the older branch:
```
git cherry-pick -m1 332e70ec077a101b7983eb73ffd2c215d7363ecf
```

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

```
git commit -am 'Backport PR #45950: CI: Set max job limit for test runs'
```

4. Push to a named branch:

```
git push YOURFORK 1.4.x:auto-backport-of-pr-45950-on-1.4.x
```

5. Create a PR against branch 1.4.x, I would have named this PR:

> "Backport PR #45950 on branch 1.4.x (CI: Set max job limit for test runs)"

And apply the correct labels and milestones.

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

Remember to remove the `Still Needs Manual Backport` label once the PR gets merged.

If these instructions are inaccurate, feel free to [suggest an improvement](https://github.com/MeeseeksBox/MeeseeksDev).
                 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 1.4.x
git pull
```

2. Cherry pick the first parent branch of the this PR on top of the older branch:
```
git cherry-pick -m1 332e70ec077a101b7983eb73ffd2c215d7363ecf
```

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

```
git commit -am 'Backport PR #45950: CI: Set max job limit for test runs'
```

4. Push to a named branch:

```
git push YOURFORK 1.4.x:auto-backport-of-pr-45950-on-1.4.x
```

5. Create a PR against branch 1.4.x, I would have named this PR:

> "Backport PR #45950 on branch 1.4.x (CI: Set max job limit for test runs)"

And apply the correct labels and milestones.

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

Remember to remove the `Still Needs Manual Backport` label once the PR gets merged.

If these instructions are inaccurate, feel free to [suggest an improvement](https://github.com/MeeseeksBox/MeeseeksDev).
                 @mroeschke if you would'nt mind putting the manual backport up @meeseeksdev backport 1.4.x
 @simonjayhawkins I put up a manual one on https://github.com/pandas-dev/pandas/pull/45977. Happy to close if the other backport PR went through okay ah yes. I missed that since I was working from the milestone tasks and didn't check open pull requests. can close either.

(on the manual ones add the PR number in the description so that a link is created. and the milestone too) I'll close the manual one I opened, thanks.