Disable scheduler legacy mode in hlt2_pp_thor test

This is base on top of !1106 (merged) which should make sure we don't have any DVCommonBase running in that test.

If that is the case, we can turn off the legacy_mode of the scheduler, which means we don't go through SysExecute anymore, avoiding the AlgExecState
Should bring a small speedup.

This is ready to be tested, but as it is based on !1106 (merged) it would have to be tested together with LHCb!3298 (merged)

cc: @sstahl

added enhancement hlt2 labels

@jedavies this is ready for a round of ci-test

assigned to @jedavies

/ci-test --merge

added ci-test-triggered label

• [2021-11-01 10:50] Validation started with lhcb-master-mr#3086
• [2021-11-01 14:20] Validation started with lhcb-master-mr#3087
• [2021-11-02 11:10] Validation started with lhcb-master-mr#3091

mentioned in merge request !1131 (closed)

added 40 commits

• 8467172f...cad69f4c - 39 commits from branch master
• f4d286d5 - disable scheduler legacy mode

Compare with previous version

assigned to @rmatev

resolved all threads

approved this merge request

merged

mentioned in commit 80123476

mentioned in issue #347 (closed)