fix building with mbedtls 3.X

[orangepizza]

per https://github.com/Mbed-TLS/mbedtls/blob/development/docs/3.0-migration-guide.md, functions with _ret prefixs replaced old without return and renamed without suffix.

[Coeur]

Thank you.
Note that we never actually use the return values, and in mbedtls 2, the implementation of non-suffixed version was just about calling the suffixed versions:
https://github.com/Mbed-TLS/mbedtls/blob/5a764e5555c64337ed17444410269ff21cb617b1/library/sha1.c#L77-L80

void mbedtls_sha1_starts(mbedtls_sha1_context *ctx)
{
    mbedtls_sha1_starts_ret(ctx);
}

So we could alternatively simplify our code here and do everything without _ret suffix, no matter the version of mbedtls?

[orangepizza]

Thank you. Note that we never actually use the return values, and in mbedtls 2, the implementation of non-suffixed version was just about calling the suffixed versions: https://github.com/Mbed-TLS/mbedtls/blob/5a764e5555c64337ed17444410269ff21cb617b1/library/sha1.c#L77-L80

void mbedtls_sha1_starts(mbedtls_sha1_context *ctx)
{
    mbedtls_sha1_starts_ret(ctx);
}

So we could alternatively simplify our code here and do everything without _ret suffix, no matter the version of mbedtls?

well if not someone complied mbedtls 2.X with MBEDTLS_DEPRECATED_REMOVED, then line above it #if !defined(MBEDTLS_DEPRECATED_REMOVED) will remove that definition

[Coeur]

Good. And best if you could also prepare a second pull request for the same changes, but cherry-picked for the 4.0.x branch.

[neheb]

Could include compat-2.x.h instead

[orangepizza]

Could include compat-2.x.h instead

Think this is better as that will be removed in mbedtls 4.x so it need to be fixed at later time anyway

[ckerr]

Sanity / macos-11 CI failure is a server issue unrelated to this PR, not a PR blocker