build: bump version to v0.3.0-alpha.rc2 #41

Job	Run time
Docker build check	4m 47s
cross compilation	15m 21s
Compilation check	48s
Format check	39s
run itests	8m 43s
run itests postgres	11m 11s
Lint check	3m 37s
go mod check	1m 5s
RPC check	1m 41s
Sqlc check	25s
test vector check	1m 18s
run unit tests (unit-race)	7m 49s
run unit tests (unit-cover)	4m 56s
run unit tests (unit dbbackend=postgres)	5m 35s
	1h 7m 55s

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