gh-40745: pythran's version_requirements.txt
    
make this consistent with the Sage's current Pythran version

4811722 was merged without the needed
bump in this file.


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URL: #40745
Reported by: Dima Pasechnik
Reviewer(s):

Author: Release Manager

build/pkgs/pythran/version_requirements.txt

@@ -1,2 +1 @@
-pythran>=0.14.0,<0.18.0
-# per https://github.com/scipy/scipy/blob/maintenance/1.15.x/pyproject.toml
+pythran>=0.18.0