fix: relax openfeature-sdk version constraint in Optimizely provider (#133)

## Summary

The Optimizely provider's gemspec currently constrains `openfeature-sdk`
to `~> 0.4.0`, which translates to `>= 0.4.0, < 0.5.0`. However, the
`openfeature-sdk` gem is now at version **0.6.4**, making the Optimizely
provider unusable with current SDK versions.

This PR relaxes the constraint to `>= 0.4.0, < 1.0`, allowing
compatibility with all pre-1.0 releases of the SDK while still guarding
against potential breaking changes in a 1.0 release.

## Changes

-
**`providers/openfeature-optimizely-provider/openfeature-optimizely-provider.gemspec`**:
Changed `spec.add_runtime_dependency "openfeature-sdk", "~> 0.4.0"` to
`spec.add_runtime_dependency "openfeature-sdk", ">= 0.4.0", "< 1.0"`

*🤖 Jose's AI agent*

---------

Signed-off-by: Jose Colella <jose.colella@gusto.com>
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: josecolella

providers/openfeature-optimizely-provider/Gemfile.lock

@@ -3,7 +3,7 @@ PATH
   specs:
     openfeature-optimizely-provider (0.1.0)
       logger
-      openfeature-sdk (~> 0.4.0)
+      openfeature-sdk (~> 0.4)
       optimizely-sdk (~> 5.0)
 
 GEM

providers/openfeature-optimizely-provider/openfeature-optimizely-provider.gemspec

@@ -27,7 +27,7 @@ Gem::Specification.new do |spec|
   spec.require_paths = ["lib"]
 
   spec.add_runtime_dependency "logger"
-  spec.add_runtime_dependency "openfeature-sdk", "~> 0.4.0"
+  spec.add_runtime_dependency "openfeature-sdk", "~> 0.4"
   spec.add_runtime_dependency "optimizely-sdk", "~> 5.0"
 
   spec.add_development_dependency "rake", "~> 13.0"