Bug#1114032: using versioned gcc-15 in the build-deps, and then using the unversioned one in debian/rules

[Matthias Klose]

Package: src:esstra
Version: 0.3.0-2

The packaging is using versioned gcc-15 in the build-deps, and then 
using the unversioned one in debian/rules.  This fails, when the 
versioned gcc is not the default one. You may want to use CC=gcc-15 
CXX=g++-15 in the rules.