segment_priority assigned incorrectly when creating flagsmith_feature_state alongside existing overrides

[deepforest]

flagsmith/flagsmith provider version 0.9.1

Description

When creating a flagsmith_feature_state segment override with segment_priority=0,
the API ignores the requested value and auto-assigns a priority based on existing
overrides in the environment. If another override already holds priority 0,
the new one gets priority 1 regardless of what was requested.

This causes Terraform to fail with:

Provider produced inconsistent result after apply
.segment_priority: was cty.NumberIntVal(0), but now cty.NumberIntVal(1).

Steps to Reproduce

1. Have a feature with two segment overrides (override_0 priority 0, override_1 priority 1)
2. Trigger a destroy+create on override_0 (e.g. via replace_triggered_by)
3. override_1 remains in the API with priority 0 during the recreate
4. Terraform creates override_0 with segment_priority=0 - API returns 1
5. Terraform errors: provider produced inconsistent result

Expected Behavior

The API should honor the segment_priority value provided on creation, or the provider
should handle priority conflicts gracefully (e.g. by reordering after creation).

Actual Behavior

The API auto-assigns segment_priority based on insertion order, ignoring the
requested value. The provider does not reconcile this mismatch.

Provider Version

flagsmith/flagsmith v0.9.1

Workaround

Pre-delete all segment overrides for the affected feature before applying, so
Terraform recreates them on a clean slate in the correct order.