Add missing header to get boost::hash in Boost 1.77

Fix compilation in against LCG nightlies after the upgrade of Boost to 1.77

added lhcb-lcg-dev3 lhcb-lcg-dev4 labels

added backport run2 label

• [2021-09-04 00:24] Validation started with lhcb-lcg-dev3#1743
• [2021-09-04 00:25] Validation started with lhcb-lcg-dev4#1758
• [2021-09-05 00:06] Validation started with lhcb-lcg-dev4#1759
• [2021-09-05 00:06] Validation started with lhcb-lcg-dev3#1744
• [2021-09-06 00:11] Validation started with lhcb-lcg-dev3#1745
• [2021-09-06 00:13] Validation started with lhcb-lcg-dev4#1760
• [2021-09-07 00:16] Validation started with lhcb-lcg-dev3#1746
• [2021-09-07 00:19] Validation started with lhcb-lcg-dev4#1761
• [2021-09-08 00:15] Validation started with lhcb-lcg-dev3#1747
• [2021-09-08 00:16] Validation started with lhcb-lcg-dev4#1762
• [2021-09-09 00:16] Validation started with lhcb-lcg-dev4#1763
• [2021-09-09 00:16] Validation started with lhcb-lcg-dev3#1748
• [2021-09-10 00:27] Validation started with lhcb-lcg-dev3#1749
• [2021-09-10 00:27] Validation started with lhcb-lcg-dev4#1764
• [2021-09-11 00:15] Validation started with lhcb-lcg-dev3#1750
• [2021-09-11 00:19] Validation started with lhcb-lcg-dev4#1765
• [2021-09-12 00:09] Validation started with lhcb-lcg-dev3#1751
• [2021-09-12 00:10] Validation started with lhcb-lcg-dev4#1766
• [2021-09-13 00:10] Validation started with lhcb-lcg-dev3#1752
• [2021-09-13 00:10] Validation started with lhcb-lcg-dev4#1767
• [2021-09-14 00:16] Validation started with lhcb-lcg-dev3#1753
• [2021-09-14 00:17] Validation started with lhcb-lcg-dev4#1768
• [2021-09-15 00:15] Validation started with lhcb-lcg-dev3#1754
• [2021-09-15 00:17] Validation started with lhcb-lcg-dev4#1769
• [2021-09-15 17:52] Validation started with lhcb-lcg-dev4#1770
• [2021-09-16 00:16] Validation started with lhcb-lcg-dev3#1755
• [2021-09-16 00:16] Validation started with lhcb-lcg-dev4#1771
• [2021-09-16 12:04] Validation started with lhcb-master-mr#2900
• [2021-09-16 15:11] Validation started with lhcb-lcg-dev4#1772
• [2021-09-17 00:27] Validation started with lhcb-lcg-dev3#1756
• [2021-09-17 00:27] Validation started with lhcb-lcg-dev4#1773

Ported to run2-patches in !3238 (merged)

removed backport run2 label

marked this merge request as ready

I've removed the draft because this trivial patch works also with the version of Boost that we pick up in the master stack, so it is ready to be tested and merged.

added bug fix label

added modernisation label

assigned to @msaur

added 57 commits

• 55c53997...5d26159b - 56 commits from branch master
• 225930e0 - Add missing header to get boost::hash in Boost 1.77

Compare with previous version

/ci-test --merge

added ci-test-triggered label

assigned to @chasse

resolved all threads

resolved all threads

merged

mentioned in commit 3ddbf8ba

added Build label

removed bug fix label