fix: use values that are representable as double in test
Values like 0.1 are not representable as a double which can result in problems, for example:
[...]/dune/common/test/hybridutilitiestest.cc:114:43: error: static assertion failed: Wrong compile time sum!
114 | static_assert(sum(numberTupleConstexpr) == 5.1, "Wrong compile time sum!");
| ~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~
[...]/dune/common/test/hybridutilitiestest.cc:114:43: note: the comparison reduces to ‘(5.09999999999999964473e+0l == 5.09999999999999999991e+0l)’
with gcc 13.2.0 on i386.