gh-36532: `pkgs/sagemath-standard`: Fix sdist
    
<!-- ^^^^^
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 -->

Fixes
#36520 (comment)
<!-- Why is this change required? What problem does it solve? -->
<!-- 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.
- [ ] 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: ...
-->
- Depends on #36520

<!-- If you're unsure about any of these, don't hesitate to ask. We're
here to help! -->
    
URL: #36532
Reported by: Matthias Köppe
Reviewer(s): François Bissey

Author: Release Manager

src/MANIFEST.in

@@ -49,6 +49,7 @@ prune sage/graphs/bliss_cpp
 prune sage/libs/coxeter3
 exclude sage/graphs/mcqd.p*
 exclude sage/libs/meataxe.p*
+exclude sage/libs/sirocco.p*
 exclude sage/matrix/matrix_gfpn_dense.p*
 exclude sage/graphs/graph_decomposition/tdlib.p*