libssh2: updated to 1.10.0

libssh2 1.10

This release includes the following enhancements and bugfixes:

o adds agent forwarding support
o adds OpenSSH Agent support on Windows
o adds ECDSA key support using the Mbed TLS backend
o adds ECDSA cert authentication
o adds diffie-hellman-group14-sha256, diffie-hellman-group16-sha512,
  diffie-hellman-group18-sha512 key exchanges
o adds support for PKIX key reading when using ed25519 with OpenSSL
o adds support for EWOULDBLOCK on VMS systems
o adds support for building with OpenSSL 3
o adds support for using FIPS mode in OpenSSL
o adds debug symbols when building with MSVC
o adds support for building on the 3DS
o adds unicode build support on Windows
o restores os400 building
o increases min, max and opt Diffie Hellman group values
o improves portiablity of the make file
o improves timeout behavior with 2FA keyboard auth
o various improvements to the Wincng backend
o fixes reading parital packet replies when using an agent
o fixes Diffie Hellman key exchange on Windows 1903+ builds
o fixes building tests with older versions of OpenSSL
o fixes possible multiple definition warnings
o fixes potential cast issues _libssh2_ecdsa_key_get_curve_type()
o fixes potential use after free if libssh2_init() is called twice
o improved linking when using Mbed TLS
o fixes call to libssh2_crypto_exit() if crypto hasn't been initialized
o fixes crash when loading public keys with no id
o fixes possible out of bounds read when exchanging keys
o fixes possible out of bounds read when reading packets
o fixes possible out of bounds read when opening an X11 connection
o fixes possible out of bounds read when ecdh host keys
o fixes possible hang when trying to read a disconnected socket
o fixes a crash when using the delayed compression option
o fixes read error with large known host entries
o fixes various warnings
o fixes various small memory leaks
o improved error handling, various detailed errors will now be reported
o builds are now using OSS-Fuzz
o builds now use autoreconf instead of a custom build script
o cmake now respects install directory
o improved CI backend
o updated HACKING-CRYPTO documentation
o use markdown file extensions
o improved unit tests

(adam)