GHA: disable building tests, apps, docs in dependencies

GHA: disable building tests, apps, docs in dependencies

Also:
- for LibreSSL download the official source tarball instead of
  using the tagged Git repo and running the build script which
  merged the OpenBSD libressl repo into it. The latter method
  was also broken at the time of this commit.

Build times:
```
                       before   after
aws-lc:                 1m55s    ~40s
libressl:               1m16s  ~1m20s
openssl-tsan:           5m47s   3m43s
openssl:                6m38s   4m49s
quictls-no-deprecated:  2m28s   1m51s
quictls:               ~6m08s   4m16s
wolfssl-all:            1m36s     52s
wolfssl-master:         1m34s     53s
wolfssl-opensslextra:     50s     32s
```

LibreSSL build options are unchanged, but by using the tarball now
instead of two repos and a generator script, it also should be faster,
and more stable.

Closes #15622