Update: transformers support to latest

[rahul-tuli]

Decompression support was temporarily disabled for Transformers versions 4.50.0 through 4.51.2 due to a compatibility issue. During that time, we constrained our dependency to transformers>=4.0,<4.50.0 to prevent breakage.

What’s Changed

• Dependency update: revised the version constraint to

  transformers>=4.0,<4.50.0,>=4.51.3  
  

• Placeholder: this change will take effect once the decompression fix is implemented and validated against Transformers 4.51.3 or newer.

Why This Matters

• Restores forward compatibility with the latest Transformers releases.
• Unlocks external integrations, for example Axolotl PR #2479, which depend on support for Transformers 4.51.3 or newer.

Testing & Validation

1. Merge this PR once the decompression fix is merged into our codebase.
2. Run the full decompression test suite against Transformers 4.51.3 or newer.

No functional changes are included here—this is purely a dependency update in anticipation of the upcoming decompression fix.

[github-actions]

👋 Hi! Thank you for contributing to llm-compressor. Please add the ready label when the PR is ready for review.

Note: This is required to complete the testing suite, please only add the label once the PR is code complete and local testing has been performed.

[dsikka]

I already have a PR for this: #1352