arrow

GH-34869: [C++] Configure alpine linux nightly job to build gtest from source (#34870)

### Rationale for this change

The nightly test is currently failing with an error:

```
-- Found GTest: /usr/lib/cmake/GTest/GTestConfig.cmake (found suitable version "1.11.0", minimum required is "1.10.0")  
CMake Error at cmake_modules/ThirdpartyToolchain.cmake:2236 (message):
  System GTest is built with a C++ standard lower than 17.  Use bundled GTest
  via passing in CMake flag

  -DGTest_SOURCE="BUNDLED"
```

### What changes are included in this PR?

Changes the alpine linux nightly test to use `-DGTest_SOURCE="BUNDLED"`

### Are these changes tested?

Yes, by the nightly test itself.

### Are there any user-facing changes?

No
* Closes: #34869

Authored-by: Weston Pace <weston.pace@gmail.com>
Signed-off-by: Sutou Kouhei <kou@clear-code.com>