/usr/bin/az wrapper breaks when used as a symlink as of version 2.22.0

> ### `az feedback` auto-generates most of the information requested below, as of CLI version 2.0.62

**Describe the bug**

When the az command run by the user is a symlink to the actual /usr/bin/az, for example /usr/local/bin/az->/usr/bin/az, the az wrapper complains it cannot find the azure module.

**To Reproduce**

yum -y install azure-cli
ln -sf /usr/bin/az /usr/local/bin/az
/usr/local/bin/az --version
/usr/bin/python3: Error while finding module specification for 'azure.cli' (ModuleNotFoundError: No module named 'azure')

**Expected behavior**

azcli version output

**Environment summary**

yum, CentOS:7:latest, bash

**Additional context**

Introduced with https://github.com/Azure/azure-cli/commit/753a11c87575fedcc7425d4e34d332b17d8cd17b in the file scripts/release/rpm/azure-cli.spec

The removal of the hardcoded /usr/bin/python3 also has some implications for users running venvs as well.