Fix doc build GLIBCXX_3.4.30 not found (#2376)

Summary:
The hack is from pytorch/pytorch#121547.  This is to fix the failing doc build on 22.04, i.e. https://github.com/pytorch/executorch/actions/runs/8167685547/job/22328481328

```
ImportError: /opt/conda/envs/py_3.10/bin/../lib/libstdc++.so.6: version `GLIBCXX_3.4.30' not found (required by /opt/conda/envs/py_3.10/lib/python3.10/site-packages/torch/lib/libtorch_python.so)
```

Pull Request resolved: #2376

Reviewed By: guangy10

Differential Revision: D54818139

Pulled By: huydhn

fbshipit-source-id: aad8408908ef52f15a32395c31cc1698cd337c6b

Author: huydhn

.ci/docker/common/install_conda.sh

@@ -44,13 +44,15 @@ install_pip_dependencies() {
 }
 
 fix_conda_ubuntu_libstdcxx() {
+  cat /etc/issue
   # WARNING: This is a HACK from PyTorch core to be able to build PyTorch on 22.04.
-  # The issue still exists with the latest conda 23.10.0-1 at the time of writing
-  # (2023/11/16).
+  # Specifically, ubuntu-20+ all comes lib libstdc++ newer than 3.30+, but anaconda
+  # is stuck with 3.29. So, remove libstdc++6.so.3.29 as installed by
+  # https://anaconda.org/anaconda/libstdcxx-ng/files?version=11.2.0
   #
   # PyTorch sev: https://github.com/pytorch/pytorch/issues/105248
   # Ref: https://github.com/pytorch/pytorch/blob/main/.ci/docker/common/install_conda.sh
-  if grep -e "[12][82].04.[623]" /etc/issue >/dev/null; then
+  if grep -e "2[02].04." /etc/issue >/dev/null; then
     rm "/opt/conda/envs/py_${PYTHON_VERSION}/lib/libstdc++.so.6"
   fi
 }