New deprecations
   * The following cryptographic mechanisms are planned to be removed
     in Mbed TLS 4.0:
     - DES (including 3DES).
     - PKCS#1v1.5 encryption/decryption (RSAES-PKCS1-v1_5).
       (OAEP, PSS, and PKCS#1v1.5 signature are staying.)
     - Finite-field Diffie-Hellman with custom groups.
       (RFC 7919 groups remain supported.)
     - Elliptic curves of size 225 bits or less.
   * The following cipher suites are planned to be removed from (D)TLS 1.2
     in Mbed TLS 4.0:
     - TLS_RSA_* (including TLS_RSA_PSK_*), i.e. cipher suites using
       RSA decryption.
       (RSA signatures, i.e. TLS_ECDHE_RSA_*, are staying.)
     - TLS_ECDH_*, i.e. cipher suites using static ECDH.
       (Ephemeral ECDH, i.e. TLS_ECDHE_*, is staying.)
     - TLS_DHE_*, i.e. cipher suites using finite-field Diffie-Hellman.
       (Ephemeral ECDH, i.e. TLS_ECDHE_*, is staying.)
     - TLS_*CBC*, i.e. all cipher suites using CBC.
   * The following low-level application interfaces are planned to be removed
     from the public API in Mbed TLS 4.0:
     - Hashes: hkdf.h, md5.h, ripemd160.h, sha1.h, sha3.h, sha256.h, sha512.h;
     - Random generation: ctr_drbg.h, hmac_drbg.h, entropy.h;
     - Ciphers and modes: aes.h, aria.h, camellia.h, chacha20.h, chachapoly.h,
       cipher.h, cmac.h, gcm.h, poly1305.h;
     - Private key encryption mechanisms: pkcs5.h, pkcs12.h.
     - Asymmetric cryptography: bignum.h, dhm.h, ecdh.h, ecdsa.h, ecjpake.h,
       ecp.h, rsa.h.
     The cryptographic mechanisms remain present, but they will only be
     accessible via the PSA API (psa_xxx functions introduced gradually
     starting with Mbed TLS 2.17) and, where relevant, `pk.h`.
     For guidance on migrating application code to the PSA API, please consult
     the PSA transition guide (docs/psa-transition.md).
   * The following integration interfaces are planned to be removed
     in Mbed TLS 4.0:
     - MBEDTLS_xxx_ALT replacement of cryptographic modules and functions.
       Use PSA transparent drivers instead.
     - MBEDTLS_PK_RSA_ALT and MBEDTLS_PSA_CRYPTO_SE_C.
       Use PSA opaque drivers instead.