ci: Add Dependabot #446

Job	Run time
Pass MSRV values to other jobs	3s
clippy/stable	23s
format/nightly	15s
miri	8m 32s
cargo-careful	1m 53s
docs/nightly	22s
cross_test/s390x-unknown-linux-gnu/stable	8m 13s
nostd/thumbv6m-none-eabi/stable	12s
cross_test/i686-unknown-linux-gnu/stable	1m 26s
blas-msrv	52s
tests/stable	2m 43s
tests/1.64.0	3m 41s
tests/nightly	2m 46s
tests/beta	2m 38s
conclusion	2s
	34m 1s

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