add Python black box tests to Python CI

(first attempt will need follow-on sw tweaks)

.github/workflows/test-python.yml

@@ -50,3 +50,6 @@ jobs:
         run: |
           pip install -e .
           python timezone_solar/tests
+      - name: Run black box tests
+        run: |
+          prove test/cli-test-python.t

test/cli-test-python.t

@@ -0,0 +1,23 @@
+#!/usr/bin/env perl
+# cli-test-python.t - run LongitudeTZ black box tests for Python implementation
+# (this script is in Perl for 'prove' program to launch the tests consistently)
+# by Ian Kluft (IKLUFT), [email protected]
+# created 05/09/2024
+
+use strict;
+use warnings;
+use Config;
+use File::Basename;
+use FindBin qw($Bin);
+
+# collect parameters
+my $debug = ( $ENV{LONGITUDE_TZ_TEST_DEBUG} // 0 ) ? 1 : 0;
+my $bin_dir = $Bin;
+my $tree_root = dirname($bin_dir);
+my $perl_path = $Config{perlpath};
+
+# run black box test command
+exec $perl_path $perl_path,
+    "$bin_dir/cli-test.pl",
+    ( $debug ? "--debug" : ()),
+    "$tree_root/src/python/scripts/lon_tz.py";