Remove the Improved performance repeated enum

[muhlemmer]

Improved performance flags are a repeated enum. We often find we are advising enabling these flags for performance tuning. We have not received any significant reports indicating the optimization don't work as expected. As such, they should be enabled by default and the flags removed.

Acceptance criteria

For each enum value:

• [ ] Remove the value from the proto files
  • [ ] Set / Get System features
  • [ ] Set / Get Instance features
  • [ ] Reserve the field number
• [ ] Remove the flag from the zitadel code, assume the default state of present.
• [ ] Remove any code which will not be called anymore

[muhlemmer]

@adlerhurst can you please estimate this issue?

[muhlemmer]

CC @stebenz

[adlerhurst]

blocked by https://github.com/zitadel/zitadel/issues/10302