[C++] Test Failure With ARROW_BUILD_TESTS=ON and ARROW_COMPUTE=OFF

[WillAyd]

Describe the bug, including details regarding any error messages, version, and platform.

I believe this is a minor regression stemming from the change in #45535

If you build Arrow tests without compute, there is a test in testing/gtest_util_test.cc that will fail because the run_end_encode function is not registered in compute:

$ cmake -S . -B build -G Ninja -DCMAKE_C_COMPILER_LAUNCHER=ccache -DCMAKE_CXX_COMPILER_LAUNCHER=ccache -DARROW_COMPUTE=OFF -DARROW_BUILD_TESTS=ON
$ cmake --build build
$ ./build/release/arrow-gtest-util-test

...

[ RUN      ] RunEndEncodeGtestUtilTest.SchemaTypeIsModified
/home/willayd/clones/arrow/cpp/src/arrow/testing/gtest_util_test.cc:303: Failure
Failed
'_error_or_value22.status()' failed with Key error: No function registered with name: run_end_encode

[  FAILED  ] RunEndEncodeGtestUtilTest.SchemaTypeIsModified (0 ms)
[----------] 1 test from RunEndEncodeGtestUtilTest (0 ms total)

[----------] Global test environment tear-down
[==========] 11 tests from 5 test suites ran. (2 ms total)
[  PASSED  ] 10 tests.
[  FAILED  ] 1 test, listed below:
[  FAILED  ] RunEndEncodeGtestUtilTest.SchemaTypeIsModified

Component(s)

C++

[wgtmac]

I ran into the same issue.

[raulcd]

Issue resolved by pull request 46161
#46161