Revert CI env change so geotiepoints comes from conda-forge

[djhoese]

Forgot that I made this change in #2835 because I needed to wait for the new python-geotiepoints to be available on conda-forge.

• [ ] Closes #xxxx
• [ ] Tests added
• [ ] Fully documented
• [ ] Add your name to AUTHORS.md if not there already

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 95.94%. Comparing base (9339a7f) to head (834f45d). Report is 336 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #2841 +/- ## ======================================= Coverage 95.94% 95.94% ======================================= Files 366 366 Lines 53543 53561 +18 ======================================= + Hits 51371 51389 +18 Misses 2172 2172 ``` | [Flag](https://app.codecov.io/gh/pytroll/satpy/pull/2841/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=pytroll) | Coverage Δ | | |---|---|---| | [behaviourtests](https://app.codecov.io/gh/pytroll/satpy/pull/2841/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=pytroll) | `4.04% <ø> (-0.01%)` | :arrow_down: | | [unittests](https://app.codecov.io/gh/pytroll/satpy/pull/2841/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=pytroll) | `96.04% <ø> (+<0.01%)` | :arrow_up: | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=pytroll#carryforward-flags-in-the-pull-request-comment) to find out more.

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[coveralls]

Pull Request Test Coverage Report for Build 9687447409

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 96.044%

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Totals
Change from base Build 9685663864:	0.0%
Covered Lines:	51618
Relevant Lines:	53744

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💛 - Coveralls