Don't parse default postponedsizelimit (#89906)
## For Maintainers
### What?
Optimize the `parseMaxPostponedStateSize` function by using a
pre-calculated byte value for the default size limit instead of parsing
it each time.
### Why?
This optimization improves performance (though it's a very small impact)
since `parseMaxPostponedStateSize` is in the hot path for rendering. By
using a pre-calculated constant value for the default case, we avoid
unnecessary parsing operations.
### How?
- Added a constant `DEFAULT_MAX_POSTPONED_STATE_SIZE_BYTES` with the
pre-calculated value of 100MB in bytes (104,857,600)
- Modified `parseMaxPostponedStateSize` to return the pre-calculated
constant when no size is provided
- Only call `parseSizeLimit` when a custom size is specified
