skip python 3.13t since conda doesn't support it yet

Summary:
# context
* there are failures in torchrec binary validation {F1975312017}
* because conda can't support python 3.13t
```
$ conda create -n test python=3.13t
Collecting package metadata (current_repodata.json): done
Solving environment: failed with repodata from current_repodata.json, will retry with next repodata source.
Collecting package metadata (repodata.json): done
Solving environment: failed

PackagesNotFoundError: The following packages are not available from current channels:

  - python=3.13t

Current channels:

  - https://repo.anaconda.com/pkgs/main/linux-64
  - https://repo.anaconda.com/pkgs/main/noarch
  - https://repo.anaconda.com/pkgs/r/linux-64
  - https://repo.anaconda.com/pkgs/r/noarch

To search for alternate channels that may provide the conda package you're
looking for, navigate to

    https://anaconda.org

and use the search bar at the top of the page.

```

Differential Revision: D69962038

Author: TroyGarden

.github/scripts/validate_binaries.sh

@@ -9,6 +9,11 @@
 export PYTORCH_CUDA_PKG=""
 export CONDA_ENV="build_binary"
 
+if [[ ${MATRIX_PYTHON_VERSION} = '3.13t' ]]; then
+    echo "Conda doesn't support 3.13t yet, you can just try \`conda create -n test python=3.13t\`"
+    exit 0
+fi
+
 conda create -y -n "${CONDA_ENV}" python="${MATRIX_PYTHON_VERSION}"
 
 conda run -n build_binary python --version

.github/workflows/validate-nightly-binaries.yml

@@ -2,11 +2,6 @@
 name: validate-nightly-binaries
 
 on:
-  schedule:
-    # At 5:30 pm UTC (7:30 am PDT)
-    - cron: "30 17 * * *"
-  # Have the ability to trigger this job manually through the API
-  workflow_dispatch:
   push:
     branches:
       - main