Avoid unneccessary work if tests are not requested

Some tests are built (and installed, see #244) even if BUILD_TESTING is set to false.

This MR fixes the problem (note that gaudi_add_tests() already respects BUILD_TESTING).

changed milestone to %v36r9

added lhcb-gaudi-head label

• [2022-11-09 00:03] Validation started with lhcb-gaudi-head#3389
• [2022-11-09 00:22] Validation started with lhcb-run2-gaudi-head#413
• [2022-11-09 15:44] Validation started with lhcb-gaudi-head#3390
• [2022-11-09 16:10] Validation started with lhcb-gaudi-head#3391
• [2022-11-09 18:02] Validation started with lhcb-gaudi-head#3392
• [2022-11-10 00:02] Validation started with lhcb-gaudi-head#3393
• [2022-11-10 00:18] Validation started with lhcb-run2-gaudi-head#414
• [2022-11-11 00:03] Validation started with lhcb-gaudi-head#3394
• [2022-11-11 00:23] Validation started with lhcb-run2-gaudi-head#415
• [2022-11-12 00:05] Validation started with lhcb-gaudi-head#3395
• [2022-11-12 00:31] Validation started with lhcb-run2-gaudi-head#416
• [2022-11-13 00:04] Validation started with lhcb-gaudi-head#3396
• [2022-11-14 00:02] Validation started with lhcb-gaudi-head#3397
• [2022-11-15 00:04] Validation started with lhcb-gaudi-head#3398
• [2022-11-15 00:28] Validation started with lhcb-run2-gaudi-head#417

assigned to @clemenci

approved this merge request

merged

mentioned in commit 5de4967d