MINOR: [C++] Fix CMake deps for minimal Flight benchmark build

[lidavidm]

Otherwise it errors if you try to just build the Flight benchmark

[kou]

+1

[ursabot]

Benchmark runs are scheduled for baseline = 1e9eb61 and contender = 767f203. 767f203 is a master commit associated with this PR. Results will be available as each benchmark for each run completes.
Conbench compare runs links:
[Finished ⬇️0.0% ⬆️0.0%] ec2-t3-xlarge-us-east-2
[Failed ⬇️0.13% ⬆️0.03%] test-mac-arm
[Finished ⬇️0.27% ⬆️0.0%] ursa-i9-9960x
[Finished ⬇️0.24% ⬆️0.24%] ursa-thinkcentre-m75q
Buildkite builds:
[Finished] 767f203d ec2-t3-xlarge-us-east-2
[Failed] 767f203d test-mac-arm
[Finished] 767f203d ursa-i9-9960x
[Finished] 767f203d ursa-thinkcentre-m75q
[Finished] 1e9eb615 ec2-t3-xlarge-us-east-2
[Finished] 1e9eb615 test-mac-arm
[Finished] 1e9eb615 ursa-i9-9960x
[Finished] 1e9eb615 ursa-thinkcentre-m75q
Supported benchmarks:
ec2-t3-xlarge-us-east-2: Supported benchmark langs: Python, R. Runs only benchmarks with cloud = True
test-mac-arm: Supported benchmark langs: C++, Python, R
ursa-i9-9960x: Supported benchmark langs: Python, R, JavaScript
ursa-thinkcentre-m75q: Supported benchmark langs: C++, Java