Pin huggingface_hub<1.0 (#15399)

Trying to fix failing HF CI jobs. Looks like our transformers version
requires huggingface_hub<1.0, but we're installing the latest 1.0
version which just released today. Until we bump transformers, I'll just
pin our install of huggingface_hub to below 1.0.

Note that we don't pin the transformers version the same way for pip
install, so this should be a ci only issue (and hence ci only fix).

Here's an example job failure:
```
transformers 4.56.1 requires huggingface-hub<1.0,>=0.34.0, but you have huggingface-hub 1.0.0 which is incompatible.
...
/exec: line 13: huggingface-cli: command not found
```
(from
https://github.com/pytorch/executorch/actions/runs/18851188516/job/53787937311)

(cherry picked from commit 57f0dfd)

Author: GregoryComer

.github/workflows/pull.yml

@@ -307,9 +307,12 @@ jobs:
 
         PYTHON_EXECUTABLE=python bash .ci/scripts/setup-linux.sh --build-tool "cmake"
 
-        # install Llava requirements
-        bash examples/models/llama/install_requirements.sh
-        bash examples/models/llava/install_requirements.sh
+        echo "::group::Setup Huggingface"
+        pip install -U "huggingface_hub[cli]<1.0" accelerate
+        huggingface-cli login --token $SECRET_EXECUTORCH_HF_TOKEN
+        OPTIMUM_ET_VERSION=$(cat .ci/docker/ci_commit_pins/optimum-executorch.txt)
+        pip install git+https://github.com/huggingface/optimum-executorch.git@${OPTIMUM_ET_VERSION}
+        echo "::endgroup::"
 
         # run python unittest
         python -m unittest examples.models.llava.test.test_llava
@@ -625,7 +628,9 @@ jobs:
         conda activate "${CONDA_ENV}"
 
         PYTHON_EXECUTABLE=python bash .ci/scripts/setup-linux.sh --build-tool "cmake"
+        echo "::endgroup::"
 
+        echo "::group::Setup requirements"
         # install phi-3-mini requirements
         bash examples/models/phi-3-mini/install_requirements.sh
 

.github/workflows/trunk.yml

@@ -809,7 +809,7 @@ jobs:
         echo "::endgroup::"
 
         echo "::group::Setup Huggingface"
-        pip install -U "huggingface_hub[cli]" accelerate
+        pip install -U "huggingface_hub[cli]<1.0" accelerate
         huggingface-cli login --token $SECRET_EXECUTORCH_HF_TOKEN
         OPTIMUM_ET_VERSION=$(cat .ci/docker/ci_commit_pins/optimum-executorch.txt)
         pip install git+https://github.com/huggingface/optimum-executorch.git@${OPTIMUM_ET_VERSION}