umbrella: Remove `pallet-revive-fixtures` #15338

Job	Run time
check-dependency-rules	8s
check-fail-ci	10s
check-markdown	17s
check-readme	3m 3s
check-workspace	17s
preflight / preflight	43s
preflight / ci-versions	1m 7s
fmt	1m 20s
check-rust-feature-propagation	2m 30s
check-toml-format	1m 6s
check-umbrella	2m 42s
test-rust-features	2m 16s
All quick checks passed	1s
	15m 40s

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