gh-39738: update msolve to version 7.5
    
a routine update of msolve


- [x] The title is concise and informative.
- [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 and checked the documentation
preview.

### ⌛ Dependencies

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URL: #39738
Reported by: Dima Pasechnik
Reviewer(s): Frédéric Chapoton

Author: Release Manager

build/pkgs/msolve/checksums.ini

@@ -1,4 +1,4 @@
 tarball=msolve-VERSION.tar.gz
-sha1=01b7c4b7b6a7df5051c1357e69d9b1fd381d2907
-sha256=1f7cd8207836f522cbbc96f3bfbe431f794a31562be2c04ae1df981557c5d145
+sha1=5b8bbe14c9242244cd137c4848c3a2766a343f17
+sha256=e88368abfd1e1918329ff9444164ca0e304835794fec68d192a63c845ae63128
 upstream_url=https://msolve.lip6.fr/downloads/vVERSION/msolve-VERSION.tar.gz

build/pkgs/msolve/package-version.txt

@@ -1 +1 @@
-0.6.5
+0.7.5