Since we introduced the shim-x64 package to the list of excluded packages in
the commit d13612b to prevent a bug in the yum transaction set, we realized that the
definition/usage of that function was not needed anymore.

The function in question was used previously to remove the package protection
for the shim-x64 when it is installed on the system, as it was causing problems
during the conversion. With the package being listed as a package that
needs to be removed before the conversion starts, we don't have any use
anymore for that special function, as the package will never be present on
an Oracle Linux 7 system, thus, we have an unnecessary call for checking if a package
exists, because it will never exist.

What we are aiming with this issue is to remove the legacy functions and
integration tests that are related to that function.

Files that need to be changed

• https://github.com/oamg/convert2rhel/blob/main/convert2rhel/special_cases.py#L35
• https://github.com/oamg/convert2rhel/blob/main/convert2rhel/unit_tests/special_cases_test.py#L16-L22
• https://github.com/oamg/convert2rhel/blob/main/convert2rhel/unit_tests/special_cases_test.py#L92-L121

Acceptance Criteria

• Remove the shim-x64 functions that are not needed anymore from the special_cases.py
• Update the remove_excld_pkgs_epel7 integration test to include the shim-x64 package