Merge #11472: qa: Make tmpdir option an absolute path, misc cleanup

fafa003 qa: Remove never used return value of sync_with_ping (MarcoFalke)
fa9de37 qa: Make tmpdir option an absolute path (MarcoFalke)

Pull request description:

  This should fix issues with the multiwallet test and its symlinks
  when the tmpdir is a relative path.

  Rather than fixing os.symlink to work with paths relative to a
  directory descriptor, which does not work on Windows, normalize
  the path instead.

Tree-SHA512: 189690f3d065ea2f0f48e06775c86d513d0916c7c86312432e8e16df160e65539e288c2bd53d49a4180735fa940f6fcd52b506ccd7d9815651a9b1a69850dda6

test/functional/test_framework/test_framework.py

@@ -102,8 +102,11 @@ class BitcoinTestFramework():
 
         check_json_precision()
 
+        self.options.cachedir = os.path.abspath(self.options.cachedir)
+
         # Set up temp directory and start logging
         if self.options.tmpdir:
+            self.options.tmpdir = os.path.abspath(self.options.tmpdir)
             os.makedirs(self.options.tmpdir, exist_ok=False)
         else:
             self.options.tmpdir = tempfile.mkdtemp(prefix="test")