[NO-TICKET] Don't put results in benchmarking folder directly

[ivoanjo]

What does this PR do?

This PR tweaks the configuration for benchmark output results to place result files in the current directory the benchmark gets executed from, instead of placing the results in the benchmarks directory.

Motivation:

In #3810 we standardized the results output file name in benchmarks to match the benchmark name.

In that PR, we used __FILE__ as a prefix. This changed where results are placed: where previously they were placed in the current folder where the benchmarks were run from (often the root of the repo), with this PR, they started getting placed in the benchmarks directory.

This clashes with our validate_benchmarks_spec.rb that look for files in those directories, e.g. running a benchmark and then running the test suite will make the test suite fail which is somewhat annoying.

While I could've changed the tests to filter out results files, I also find it useful to place the results where I'm executing the benchmarks from, as it makes organization easier (you just run the benchmark from where you want and you get the result there ).

Additional Notes:

N/A

How to test the change?

Run the benchmarks and confirm the results file gets placed in the current folder! :)

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 97.87%. Comparing base (0ba87b9) to head (5a52a42).
Report is 18 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #3833   +/-   ##
=======================================
  Coverage   97.86%   97.87%           
=======================================
  Files        1264     1264           
  Lines       75762    75762           
  Branches     3720     3720           
=======================================
+ Hits        74146    74151    +5     
+ Misses       1616     1611    -5     

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[ivoanjo]

I need to tweak our test execution harness before merging this, it's failing with

+ cp 'benchmarks/*-results.json' /go/src/github.com/DataDog/apm-reliability/dd-trace-rb/artifacts/candidate
cp: cannot stat 'benchmarks/*-results.json': No such file or directory

[ivoanjo]

This is currently blocked by https://github.com/DataDog/benchmarking-platform/pull/92

[pr-commenter]

Benchmarks

Benchmark execution time: 2024-08-12 13:47:20

Comparing candidate commit 5a52a42 in PR branch ivoanjo/dont-put-results-in-benchmark-folder with baseline commit 0ba87b9 in branch master.

Found 2 performance improvements and 0 performance regressions! Performance is the same for 21 metrics, 2 unstable metrics.

scenario:profiler gc

• 🟩 throughput [+11090.932op/s; +11850.220op/s] or [+3.047%; +3.255%]

scenario:stack collector

• 🟩 throughput [+66.077op/s; +67.629op/s] or [+2.451%; +2.508%]