This commit replaces the LDAP client TLS config and
adds a custom list of TLS cipher suites which support
RSA key exchange (RSA kex).
Some LDAP server connections experience a significant slowdown
when these cipher suites are not available. The Go TLS stack
disables them by default. (Can be enabled via GODEBUG=tlsrsakex=1).
fixes https://github.com/minio/minio/issues/20214
With a custom list of TLS ciphers, Go can pick the TLS RSA key-exchange
cipher. Ref:
```
if c.CipherSuites != nil {
return c.CipherSuites
}
if tlsrsakex.Value() == "1" {
return defaultCipherSuitesWithRSAKex
}
```
Ref: https://cs.opensource.google/go/go/+/refs/tags/go1.22.5:src/crypto/tls/common.go;l=1017
Signed-off-by: Andreas Auernhammer <github@aead.dev>