Fix MSRV issues by re-releasing sha1, sha2, sha3, md5, and whirlpool. Take 2.

[newpavlov]

#399 has not resolved the issues. resolver = "2" leaks during publishing using the current stable toolchain and other older toolchains, so this PR temporarily comments it out. It could be a cargo bug, so I reported it in rust-lang/cargo#11047. The behavior looks intentional.

[newpavlov]

@striezel Can you confirm that the issues got resolved?

[striezel]

@newpavlov Yes, looks good to me. The new versions of the published crates can be built with rustc 1.48 again. 👍
Thank you very much.

[striezel]

Bad news:
gost94 v0.10.2 (https://docs.rs/crate/gost94/0.10.2/source/Cargo.toml) and fsb v0.1.2 (https://docs.rs/crate/fsb/0.1.2/source/Cargo.toml) also have the resolver = "2" line, so they will fail to build with older rustc versions, too.
Should I create issues for those, too?

Good news:
blake2 v0.10.4 (https://docs.rs/crate/blake2/0.10.4/source/Cargo.toml) is not affected by this issue, i. e. builds just fine. That is the MSRV problem likely got introduced after 18th February 2022 (release of blake2 v0.10.4), and earlier releases are not affected. So all other RustCrypto/hashes crates should be fine.

[newpavlov]

I will do re-releases for them right away, so I think issues are not necessary. Thank you for checking the other crates!