Remove OPENSSL_EXPORT on some internal SSL_SESSION functions

They were exported for bssl_shim, used by some of the split handshakes
machinery, but this is no longer needed.

Bug: 376969215
Change-Id: I89d284d658bd9a27c2973587443451281c064932
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/100487
Reviewed-by: Lily Chen <chlily@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
Commit-Queue: Lily Chen <chlily@google.com>
Auto-Submit: David Benjamin <davidben@google.com>

ssl/internal.h

diff --git a/ssl/internal.h b/ssl/internal.h
index 220cf99..a59ded0 100644
--- a/ssl/internal.h
+++ b/ssl/internal.h
@@ -3599,13 +3599,14 @@
 
 // SSL_SESSION_parse parses an `SSL_SESSION` from `cbs` and advances `cbs` over
 // the parsed data.
-OPENSSL_EXPORT UniquePtr<SSL_SESSION> SSL_SESSION_parse(
-    CBS *cbs, const SSL_X509_METHOD *x509_method, CRYPTO_BUFFER_POOL *pool);
+UniquePtr<SSL_SESSION> SSL_SESSION_parse(CBS *cbs,
+                                         const SSL_X509_METHOD *x509_method,
+                                         CRYPTO_BUFFER_POOL *pool);
 
 // ssl_session_serialize writes `in` to `cbb` as if it were serialising a
 // session for Session-ID resumption. It returns true on success and false on
 // error.
-OPENSSL_EXPORT bool ssl_session_serialize(const SSL_SESSION *in, CBB *cbb);
+bool ssl_session_serialize(const SSL_SESSION *in, CBB *cbb);
 
 enum class SSLSessionType {
   // The session is not resumable.