Perf issue: avoid vector copy at each insertion. #6295

Job	Run time
Discover Versions	4s
Platform Cache / Discover Platforms	4s
Platform Cache / Build Platforms (none)	1s
Run Build Workflow / Build leap (reproducible)	9m 1s
Run Build Workflow / Build leap (ubsan)	9m 51s
Run Build Workflow / Build leap (asserton)	8m 11s
Run Build Workflow / Build leap (ubuntu20)	6m 24s
Run Build Workflow / Build leap (ubuntu22)	8m 23s
Tests (ubuntu20)	3m 15s
LR Tests (ubuntu20)	24m 11s
Tests (ubuntu22)	3m 22s
NP Tests (ubuntu20)	6m 35s
LR Tests (ubuntu22)	23m 55s
Build deb packages (ubuntu20)	10m 32s
Tests (asserton)	3m 14s
NP Tests (ubuntu22)	5m 13s
LR Tests (asserton)	24m 3s
Tests (ubsan)	3m 37s
Build deb packages (ubuntu22)	9m 57s
NP Tests (asserton)	5m 9s
LR Tests (ubsan)	25m 11s
Tests (ubuntu20repro)	3m 25s
NP Tests (ubsan)	7m 40s
Build deb packages (reproducible)	8m 55s
LR Tests (ubuntu20repro)	24m 16s
Tests (ubuntu22repro)	3m 16s
NP Tests (ubuntu20repro)	6m 21s
NP Tests (ubuntu22repro)	5m 12s
LR Tests (ubuntu22repro)	24m 3s
libtester tests (ubuntu22, build-tree)	7m 33s
libtester tests (ubuntu22, make-dev-install)	9m 39s
libtester tests (ubuntu22, deb-install)	4m 20s
All Required Tests Passed	1s
	4h 54m 54s

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