properly specify incompatible pipx version

as per pypa/pipx#1390 the issue should be fixed in the next release,
so we specify this here

Author: Cube707

.github/workflows/constraints.txt

@@ -1,5 +1,5 @@
 pip==24.1.1
-pipx<1.5.0
+pipx==1.4.3,!=1.5,!=1.6.0
 nox==2023.4.22
 nox-poetry==1.0.3
 virtualenv==20.26.3