gh-36003: pkgs/sagemath-meataxe/README.rst: Remove markup unknown to PyPI
    
<!-- ^^^^^
Please provide a concise, informative and self-explanatory title.
Don't put issue numbers in there, do this in the PR body below.
For example, instead of "Fixes #1234" use "Introduce new method to
calculate 1+1"
-->
<!-- Describe your changes here in detail -->

<!-- Why is this change required? What problem does it solve? -->
This fixes a failure that currently stops our distributions from being
published to PyPI:
https://github.com/sagemath/sage/actions/runs/5706565883/job/15462388715
#step:7:28

<!-- If this PR resolves an open issue, please link to it here. For
example "Fixes #12345". -->
<!-- If your change requires a documentation PR, please link it
appropriately. -->

### 📝 Checklist

<!-- Put an `x` in all the boxes that apply. -->
<!-- If your change requires a documentation PR, please link it
appropriately -->
<!-- If you're unsure about any of these, don't hesitate to ask. We're
here to help! -->
<!-- Feel free to remove irrelevant items. -->

- [x] The title is concise, informative, and self-explanatory.
- [x] The description explains in detail what this PR is about.
- [ ] I have linked a relevant issue or discussion.
- [ ] I have created tests covering the changes.
- [ ] I have updated the documentation accordingly.

### ⌛ Dependencies

<!-- List all open PRs that this PR logically depends on
- #12345: short description why this is a dependency
- #34567: ...
-->

<!-- If you're unsure about any of these, don't hesitate to ask. We're
here to help! -->
    
URL: #36003
Reported by: Matthias Köppe
Reviewer(s): François Bissey

Author: Release Manager

pkgs/sagemath-meataxe/README.rst

@@ -28,8 +28,8 @@ About this pip-installable source distribution
 This pip-installable source distribution ``sagemath-meataxe`` is a small
 optional distribution for use with ``sagemath-standard``.
 
-This distribution provides the SageMath modules :mod:`sage.libs.meataxe`
-and :mod:`sage.matrix.matrix_gfpn_dense`.
+This distribution provides the SageMath modules ``sage.libs.meataxe``
+and ``sage.matrix.matrix_gfpn_dense``.
 
 It provides a specialized implementation of matrices over the finite field F_q, where
 q <= 255, using the `SharedMeatAxe <http://users.minet.uni-jena.de/~king/SharedMeatAxe/>`