Check Python version on application launch (#393)

* Check that the minimum required Python (3.8) version is used.

Prints a descriptive error message, rather than a cryptic import
failure, if minimum Python version is not met.

Internal ticket SWDEV-477233.


* Disable the RPM mangling of shebangs.

The are changing the `#!/usr/bin/python3` to `#!/usr/libexec/platform-python`.
With this set, omniperf is always using the platform installed version
of python, which is python 3.6 on RHEL 8. Using virtual environments,
like conda, did not work.

* Fix pylint issues

---------

Signed-off-by: David Galiffi <David.Galiffi@amd.com>

docs/install/core-install.rst

@@ -32,7 +32,7 @@ right for you.
    :width: 800
 
 .. _core-install:
- 
+
 Core installation
 =================
 
@@ -44,6 +44,12 @@ installation.
 * CMake ``>= 3.19``
 * ROCm ``>= 5.7.1``
 
+.. note::
+
+   Omniperf will use the first version of ``Python3`` found in your system's
+   ``PATH``. If the default version of Python3 is older than 3.8, you may need to
+   update your system's ``PATH`` to point to a newer version of Python3.
+
 Omniperf depends on a number of Python packages documented in the top-level
 ``requirements.txt`` file. Install these *before* configuring Omniperf.
 
@@ -66,6 +72,16 @@ following steps illustrate how to install the necessary Python dependencies
 using `pip <https://packaging.python.org/en/latest/>`_ and Omniperf into a
 shared location controlled by the ``INSTALL_DIR`` environment variable.
 
+.. tip::
+
+   To always run Omniperf with a particular version of python, you can create a
+   bash alias. For example, to run Omniperf with Python 3.10, you can run the
+   following command:
+
+   .. code-block:: shell
+
+      alias omniperf-mypython="/usr/bin/python3.10 /opt/rocm/bin/omniperf"
+
 .. _core-install-cmake-vars:
 
 Configuration variables
@@ -208,21 +224,21 @@ software stack.
       .. code-block:: shell
 
          $ sudo apt install omniperf
-         $ pip install -r /opt/rocm/libexec/omniperf/requirements.txt
+         $ python3 -m pip install -r /opt/rocm/libexec/omniperf/requirements.txt
 
    .. tab-item:: Red Hat Enterprise Linux
 
       .. code-block:: shell
 
          $ sudo dnf install omniperf
-         $ pip install -r /opt/rocm/libexec/omniperf/requirements.txt
+         $ python3 -m pip install -r /opt/rocm/libexec/omniperf/requirements.txt
 
    .. tab-item:: SUSE Linux Enterprise Server
 
       .. code-block:: shell
 
          $ sudo zypper install omniperf
-         $ pip install -r /opt/rocm/libexec/omniperf/requirements.txt
+         $ python3 -m pip install -r /opt/rocm/libexec/omniperf/requirements.txt
 
 .. _core-install-rocprof-var: