apacheGH-41725: [Python] CMake: ignore Parquet encryption option if P…

…arquet itself is not enabled (fix Java integration build) (apache#41776)

### Rationale for this change

Because of refactoring in apache#41480, explicitly enabling `PYARROW_WITH_PARQUET_ENCRYPTION` without enabling `PYARROW_WITH_PARQUET` (and without Arrow C++ being built with Parquet support) now raises an error, while before we checked in `setup.py` that both were enabled for enabling encryption support. This patch mimics that logic in CMakeLists.txt with a warning added.

### What changes are included in this PR?

When PyArrow with Parquet Encryption is enabled but PyArrow with Parquet itself is not, ignore the encryption setting, but warn about it.

### Are these changes tested?

Yes

* GitHub Issue: apache#41725

Authored-by: Joris Van den Bossche <[email protected]>
Signed-off-by: Sutou Kouhei <[email protected]>

python/CMakeLists.txt

@@ -370,12 +370,18 @@ if(PYARROW_BUILD_ACERO)
   endif()
 endif()
 
-if(PYARROW_BUILD_PARQUET OR PYARROW_BUILD_PARQUET_ENCRYPTION)
+if(PYARROW_BUILD_PARQUET)
   message(STATUS "Building PyArrow with Parquet")
   if(NOT ARROW_PARQUET)
     message(FATAL_ERROR "You must build Arrow C++ with ARROW_PARQUET=ON")
   endif()
   find_package(Parquet REQUIRED)
+else()
+  if(PYARROW_BUILD_PARQUET_ENCRYPTION)
+    message(WARNING "Building PyArrow with Parquet Encryption is requested, but Parquet itself is not enabled. Ignoring the Parquet Encryption setting."
+    )
+    set(PYARROW_BUILD_PARQUET_ENCRYPTION OFF)
+  endif()
 endif()
 
 # Check for only Arrow C++ options