resolve: only write one ELF note for libcrypto

resolve: only write one ELF note for libcrypto

systemd-resolved has 2 contradictory ELF notes for libcrypto:

```
$ systemd-analyze dlopen-metadata /usr/lib/systemd/systemd-resolved
FEATURE   DESCRIPTION                                SONAME         PRIORITY
libcrypto Support for cryptographic operations       libcrypto.so.3 recommended
idn       Support for internationalized domain names libidn2.so.0   recommended
libcrypto Support for cryptographic operations       libcrypto.so.3 required
libssl    Support for TLS                            libssl.so.3    required
```

In order to have a single note, condition its priority based on whether
DNS-over-TLS is enabled.