Update version to 39.0

Part of #318 (closed)

changed milestone to %v39r0

added all-slots label

approved this merge request

• [2024-07-18 00:05] Validation started with lhcb-gaudi-head#3958
• [2024-07-18 00:19] Validation started with lhcb-run2-gaudi-head#796
• [2024-07-18 00:23] Validation started with lhcb-sim10-gaudi-head#532
• [2024-07-19 00:03] Validation started with lhcb-gaudi-head#3959
• [2024-07-19 00:07] Validation started with lhcb-run2-gaudi-head#797
• [2024-07-19 00:35] Validation started with lhcb-gaudi-head#3959
• [2024-07-20 00:04] Validation started with lhcb-gaudi-head#3960
• [2024-07-20 00:09] Validation started with lhcb-lcg-dev3lhcb#447
• [2024-07-20 00:10] Validation started with lhcb-lcg-dev4lhcb#456
• [2024-07-20 00:16] Validation started with lhcb-run2-patches-dev4#1717
• [2024-07-20 00:18] Validation started with lhcb-run2-gaudi-head#798
• [2024-07-20 00:25] Validation started with lhcb-sim10-gaudi-head#533
• [2024-07-21 00:03] Validation started with lhcb-gaudi-head#3961
• [2024-07-21 00:15] Validation started with lhcb-sanitizers#1126
• [2024-07-23 00:03] Validation started with lhcb-gaudi-head#3962
• [2024-07-24 00:03] Validation started with lhcb-gaudi-head#3963
• [2024-07-24 00:03] Validation started with lhcb-sim10-gaudi-head#534

merged

mentioned in commit 003c91f5