Pelican build action deprecation warnings on cmake of libcmark

In the `pelican` action:

```
+ cmake --version
cmake version 3.31.6

CMake suite maintained and supported by Kitware (kitware.com/cmake).
+ cmake -DCMARK_TESTS=OFF -DCMARK_STATIC=OFF ..
CMake Deprecation Warning at CMakeLists.txt:1 (cmake_minimum_required):
Compatibility with CMake < 3.10 will be removed from a future version of
CMake.

Update the VERSION argument value. Or, use the ... syntax
to tell CMake that the project requires at least but has been updated
to work with policies introduced by or earlier.

CMake Deprecation Warning at CMakeLists.txt:6 (cmake_policy):
The OLD behavior for policy CMP0048 will be removed from a future version
of CMake.

The cmake-policies(7) manual explains that the OLD behaviors of all
policies are deprecated and that a policy should be set to OLD only under
specific short-term circumstances. Projects should be ported to the NEW
behavior and not rely on setting a policy to OLD.

CMake Deprecation Warning at extensions/CMakeLists.txt:1 (cmake_minimum_required):
Compatibility with CMake < 3.10 will be removed from a future version of
CMake.

Update the VERSION argument value. Or, use the ... syntax
to tell CMake that the project requires at least but has been updated
to work with policies introduced by or earlier.
```