Refactor - Makes loader-v4 the default #9911

Job	Run time
cargo-test-sbf (token/program)	9m 9s
cargo-test-sbf (instruction-padding/program, token/program-2022, token/program-2022-test)	15m 56s
cargo-test-sbf (associated-token-account/program, associated-token-account/program-test)	9m 3s
cargo-test-sbf (token-upgrade/program)	10m 32s
check	2m 56s
cargo-test-sbf (feature-proposal/program)	7m 22s
cargo-test-sbf (governance/addin-mock/program, governance/program)	12m 36s
cargo-test-sbf (memo/program)	8m 11s
test (token/cli, token/program, token/program-2022, associated-token-account/program, instruction...	18m 24s
cargo-test-sbf (name-service/program)	8m 2s
test (single-pool/cli, single-pool/program)	17m 44s
cargo-test-sbf (stake-pool/program)	10m 17s
test (token-upgrade/cli, token-upgrade/program)	17m 43s
cargo-test-sbf (single-pool/program)	9m 11s
	2h 37m 6s

Provide feedback