- change default LCG to 103
- run build and test in one job
- test centos7 and el9
- use LCG 102b x86_64-centos7-gcc11-opt as minimum version

See merge request !1474

See merge request !1469

Closes #262

See merge request !1467

See merge request !1466

See merge request !1465

See merge request !1464

See merge request !1461

See merge request !1460

See merge request !1462

If `QMTEST_DISABLE_FIXTURES_REQUIRED` is truthy, a failing prerequisite
test will not cause the test depending on it to be skipped.

Workaround for #216

the additions of decltype checks in Gaudi::Property are needed to avoid
that fmtlib confuses Gaudi::Property for a range.

And added a test checking new behavior.
Basically integer arithmetic was broken as the index computation was optimized by precomputing the bin width. This lead to 0 bin width when < 1. Now fixed.

Essentially to be able to inspect the configuration of histograms, e.g. nb bins, min/max value, etc
These methods were so far protected for unknown reasons

See merge request !1459

See merge request !1456

Closes #266

See merge request !1455

See merge request !1457

See merge request !1452

See merge request !1454

See merge request !1453

See merge request !1451

See merge request !1450

See merge request !1449