Fix MSRV for skip-partial-aggregation #786

Job	Run time
cargo check	4m 48s
Check cargo fmt	35s
cargo test (macos)	11m 14s
cargo test (macos-aarch64)	10m 34s
build with wasm-pack	2m 24s
Verify MSRV (Min Supported Rust Version)	6m 25s
Verify Vendored Code	1m 3s
cargo test (win64)	43m 30s
cargo test pyarrow (amd64)	3m 0s
verify benchmark results (amd64)	10m 55s
check Cargo.toml formatting	2m 52s
clippy	5m 14s
check configs.md is up-to-date	2m 45s
cargo test hash collisions (amd64)	13m 31s
cargo doc	3m 42s
cargo test (amd64)	9m 59s
cargo test datafusion-cli (amd64)	3m 47s
cargo test doc (amd64)	13m 51s
cargo examples (amd64)	12m 35s
Run sqllogictest with Postgres runner	3m 13s
	2h 45m 57s

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