{2023.06} get changed/new files from PR.diff file

[trz42]

Reverts method to determine which easystack files have been changed back to original commit in #351

[eessi-bot]

Instance eessi-bot-citc-aws is configured to build:

• arch x86_64/generic for repo eessi-2021.12
• arch x86_64/generic for repo eessi.org-2023.06-compat
• arch x86_64/generic for repo eessi.io-2023.06-compat
• arch x86_64/generic for repo eessi-2023.06-software
• arch x86_64/intel/haswell for repo eessi-2021.12
• arch x86_64/intel/haswell for repo eessi.org-2023.06-compat
• arch x86_64/intel/haswell for repo eessi.io-2023.06-compat
• arch x86_64/intel/haswell for repo eessi-2023.06-software
• arch x86_64/intel/skylake_avx512 for repo eessi-2021.12
• arch x86_64/intel/skylake_avx512 for repo eessi.org-2023.06-compat
• arch x86_64/intel/skylake_avx512 for repo eessi.io-2023.06-compat
• arch x86_64/intel/skylake_avx512 for repo eessi-2023.06-software
• arch x86_64/amd/zen2 for repo eessi-2021.12
• arch x86_64/amd/zen2 for repo eessi.org-2023.06-compat
• arch x86_64/amd/zen2 for repo eessi.io-2023.06-compat
• arch x86_64/amd/zen2 for repo eessi-2023.06-software
• arch x86_64/amd/zen3 for repo eessi-2021.12
• arch x86_64/amd/zen3 for repo eessi.org-2023.06-compat
• arch x86_64/amd/zen3 for repo eessi.io-2023.06-compat
• arch x86_64/amd/zen3 for repo eessi-2023.06-software
• arch aarch64/generic for repo eessi-2021.12
• arch aarch64/generic for repo eessi.org-2023.06-compat
• arch aarch64/generic for repo eessi.io-2023.06-compat
• arch aarch64/generic for repo eessi-2023.06-software
• arch aarch64/neoverse_n1 for repo eessi-2021.12
• arch aarch64/neoverse_n1 for repo eessi.org-2023.06-compat
• arch aarch64/neoverse_n1 for repo eessi.io-2023.06-compat
• arch aarch64/neoverse_n1 for repo eessi-2023.06-software
• arch aarch64/neoverse_v1 for repo eessi-2021.12
• arch aarch64/neoverse_v1 for repo eessi.org-2023.06-compat
• arch aarch64/neoverse_v1 for repo eessi.io-2023.06-compat
• arch aarch64/neoverse_v1 for repo eessi-2023.06-software

[boegel]

I've started looking into a better way to do this on the bot side, but haven't gotten very far yet, so this is good enough in the short term...