Debian 12-compatible minimum openssl crates

Crate `openssl-sys = 0.9.55` seems to look for OpenSSL v1.x, which is
not available to Debian 12. Pinning it up to 0.9.64 makes it match with
OpenSSL 3.x which *is* available.

HOWEVER! Building the crate on Debian 11 works just fine. Pinning the
dependencies this way is an error as I neither use them directly, nor
have any reason to depend on this specific version.

Cargo can't know about the distro version. Maybe I can use crate
features to select different openssl-sys crates? Further work required.

Cargo.toml

@@ -13,6 +13,15 @@ tokio = { version = "1.24.2", features = ["macros", "rt-multi-thread"] }
 # Fixes: Reqwest uses too-old version of crate `log`
 log = "0.4.6"
 
+# Debian 12 uses OpenSSL 3.x and older libssl-sys crates are angry about that
+
+# Fixes: native lib lookup.
+# Causes: missing item in crate `ffi`
+openssl-sys = "0.9.64" 
+
+# Fixes: missing item in crate `ffi` (from openssl-sys)
+openssl = "0.10.35"
+
 # End Grand-dependency Pins	----
 
 # Packages available in Debian (Sid)