Modernize python and update pylint (#5096)

Update code to conform to the newer version of pylint available in
ubuntu-22.04, with few exceptions:
    - disabled `import-outside-toplevel` for `main()` in
      `jerry_client.py`
    - disabled `consider-using-with` for the logfile of `TestSuite` in
      `test262-harness.py` as using `with` is not practical in that case

Update test262-harness.py to use argparse instead of the now deprecated
optparse

Rename variables in jerry_client_main.py that redefined python builtins
or shadowed variables from an outer scope

Update python files to use f-stirngs

Add minimum python versions (3.6 and 3.8) to the CI jobs: without it the
default python version did not support the `with` statement for
`subprocess.Popen` used in `build.py` on macos, or in some cases f-stirngs

Remove `from __future__` imports that are no-ops in python 3

Remove shebang from non executable files

Re-enable most pylint checkers, except `missing-docstring`

JerryScript-DCO-1.0-Signed-off-by: Máté Tokodi mate.tokodi@szteszoftver.hu

tools/runners/run-unittests.py

@@ -14,7 +14,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from __future__ import print_function
 import argparse
 import glob
 import os
@@ -71,7 +70,7 @@ def main(args):
                 util.print_test_result(tested, total, True, 'PASS', test_path)
         except subprocess.CalledProcessError as err:
             failed += 1
-            util.print_test_result(tested, total, False, 'FAIL (%d)' % err.returncode, test_path)
+            util.print_test_result(tested, total, False, f'FAIL ({err.returncode})', test_path)
             print("================================================")
             print(err.output)
             print("================================================")