configure.py: don't use deprecated mktemp()

configure.py uses the deprecated Python function tempfile.mktemp().
Because this function is labeled a "security risk" it is also a magnet
for automated security scanners... So let's replace it with the
recommended tempfile.mkstemp() and avoid future complaints.

The actual security implications of this mktemp() call is negligible to
non-existent: First it's just the build process (configure.py), not
the build product itself. Second, the worst that an attacker (which
needs to run in the build machine!) can do is to cause a compilation
test in configure.py to fail because it can't write to its output file.

Reported by @srikanthprathi

Refs #997

Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20220111121412.609430-1-nyh@scylladb.com>

configure.py

@@ -42,7 +42,8 @@ def ensure_tmp_dir_exists():
 def try_compile_and_link(compiler, source = '', flags = []):
     ensure_tmp_dir_exists()
     with tempfile.NamedTemporaryFile() as sfile:
-        ofile = tempfile.mktemp()
+        ofd, ofile = tempfile.mkstemp()
+        os.close(ofd)
         try:
             sfile.file.write(bytes(source, 'utf-8'))
             sfile.file.flush()