[202205] Revert the show-techsupport optimization PR's (#2581)

- What I did
Reverted PRs because they caused the degradation that some files are missing in show techsupport archive.

- How I did it
Reverts the following 
e1c8243 [202205][generate_dump] Fix for a deletion flow for all secret files in the techsupport dump (#2572)
f45dcfb [generate_dump] Optimize the execution time of 'show techsupport' CLI by paraller function execution (#2565)
93172c4 [202205] [generate_dump] Optimize the execution time of the 'show techsupport' script to 5-10% by reducing calls to the 'tar append' operation (#2562)