chore(deps): bump transformers from 4.48.3 to 4.55.2 in /backend/python/coqui (#6096)

chore(deps): bump transformers in /backend/python/coqui

Bumps [transformers](https://github.com/huggingface/transformers) from 4.48.3 to 4.55.2.
- [Release notes](https://github.com/huggingface/transformers/releases)
- [Commits](https://github.com/huggingface/transformers/compare/v4.48.3...v4.55.2)

---
updated-dependencies:
- dependency-name: transformers
  dependency-version: 4.55.2
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

backend/python/coqui/requirements-cpu.txt

@@ -1,4 +1,4 @@
-transformers==4.48.3
+transformers==4.55.2
 accelerate
 torch==2.8.0
 coqui-tts

backend/python/coqui/requirements-cublas11.txt

@@ -1,6 +1,6 @@
 --extra-index-url https://download.pytorch.org/whl/cu118
 torch==2.8.0
 torchaudio==2.4.1+cu118
-transformers==4.48.3
+transformers==4.55.2
 accelerate
 coqui-tts

backend/python/coqui/requirements-cublas12.txt

@@ -1,5 +1,5 @@
 torch==2.8.0
 torchaudio==2.4.1
-transformers==4.48.3
+transformers==4.55.2
 accelerate
 coqui-tts

backend/python/coqui/requirements-hipblas.txt

@@ -1,6 +1,6 @@
 --extra-index-url https://download.pytorch.org/whl/rocm6.0
 torch==2.8.0
 torchaudio==2.4.1+rocm6.0
-transformers==4.48.3
+transformers==4.55.2
 accelerate
 coqui-tts

backend/python/coqui/requirements-intel.txt

@@ -5,6 +5,6 @@ torchaudio==2.3.1+cxx11.abi
 oneccl_bind_pt==2.3.100+xpu
 optimum[openvino]
 setuptools
-transformers==4.48.3
+transformers==4.55.2
 accelerate
 coqui-tts