Reduce release package size and clean publish output

[Marc-André Moreau (mamoreau-devolutions)]

Summary

• prune staged PDBs larger than 1 MiB from local and CI release packages
• allow the expected System.Diagnostics.EventLog.Messages.dll publish merge so arm64 packaging succeeds
• exclude duplicate native elevator assets from the WinUI project publish output

Validation

• inspected x64 release artifact contents after CI dry run
• reran the arm64 workflow after the merge fix and confirmed packaging succeeded
• verified the arm64 zip contains ARM64 binaries and no AMD64 payload files
• confirmed shipped PDBs in the release zips total about 1.82 MiB with no PDB above 1 MiB