github: Adapt to switch to Ubuntu 22.04 for ubuntu-latest

github: Adapt to switch to Ubuntu 22.04 for ubuntu-latest

Ubuntu 22.04 ships OpenSSL 3, which requires debug symbols so we can
whitelist leaks because we don't deinitialize the library.  And because
the shipped library is not built with `-fno-omit-frame-pointer`, the
build with AddressSanitizer can't use its fast stack unwind method.
However, the previous workaround for DTLS handling with glibc apparently
isn't necessary anymore.

In the custom OpenSSL build we drop no-stdio as that lets the configure
check for libldns fail because ERR_print_errors_fp@OPENSSL_3.0.0 is not
found.

For ccache, the default path to the cache directory has changed.

Also simplified the NM tests as there is only one build since
085daf474330 ("nm: Remove old libnm-glib compat stuff").