execution: fix split scheduler preservation for late subscribers (P2300) #2032

Job	Run time
configure-core-core_local-components	31m 15s
03-agas_base-algorithms (142 tests)	36m 34s
01-1d_stencil-iostreams (142 tests)	29m 47s
05-cache-config (142 tests)	18m 48s
09-iterator_support-preprocessor (142 tests)	22m 5s
04-algorithms-batch_environments (142 tests)	30m 32s
08-include-iterator_support (142 tests)	21m 56s
07-executors-include (142 tests)	24m 38s
02-iostreams-agas_base (142 tests)	29m 6s
06-config-executors (142 tests)	16m 15s
11-segmented_algorithms-threading_base (142 tests)	17m 53s
12-threading_base-replicate (142 tests)	30m 58s
10-preprocessor-segmented_algorithms (142 tests)	24m 23s
19-iterator_support-segmented_algorithms (142 tests)	39m 31s
18-execution-iterator_support (142 tests)	20m 51s
17-async_combinators-execution (142 tests)	35m 35s
13-replicate-executors (142 tests)	32m 18s
16-container_algorithms-async_colocated (142 tests)	39m 49s
14-executors-algorithms (142 tests)	28m 56s
15-algorithms-container_algorithms (142 tests)	47m 21s
20-segmented_algorithms-version (140 tests)	39m 25s
	10h 17m 56s

Provide feedback