🩹 Lower numpy version to 2.0.1 as required by pyglotaran

Fixes:

The conflict is caused by:
    The user requested numpy==2.1.0
    matplotlib 3.9.2 depends on numpy>=1.23
    pyglotaran 0.7.3 depends on numpy<2.1 and >=1.21.2

requirements_pinned.txt

@@ -1,7 +1,7 @@
 # Runtime dependencies
 
 cycler==0.12.1
-numpy==2.1.0
+numpy==2.0.1
 matplotlib==3.9.2
 pyglotaran==0.7.3
 tabulate==0.9.0