On macOS, if you have not installed something that depends on `xz`, then your
system may lack `lzma`, resulting in a build error similar to:
```
Downloading libarchive-3.6.0.tar.xz completed [6250.61k]
libarchive/3.6.0:
ERROR: libarchive/3.6.0: Error in source() method, line 120
get(self, **self.conan_data["sources"][self.version], strip_root=True)
ReadError: file could not be opened successfully:
- method gz: ReadError('not a gzip file')
- method bz2: ReadError('not a bzip2 file')
- method xz: CompressionError('lzma module is not available')
- method tar: ReadError('invalid header')
```
The solution is to ensure that `lzma` is installed by installing `xz`.
* Remove obsolete build instructions.
* By using Conan, builders can choose which dependencies specifically to
build and link as shared objects.
* Refactor the build instructions based on the plan in #4433.
