ci: add benchmarks/run_tests.sh (#6043)
Tested locally with:
```
$ test/benchmarks/run_tests.sh -L
[...]
+ make -C /src/pytorch/xla/test/benchmarks all
make: Entering directory '/src/pytorch/xla/test/benchmarks'
AGGREGATE --accelerator=a6000 --test=inference --report=speedup
DIFF a6000.inference.speedup.test
RM a6000.inference.speedup.test.tmp
AGGREGATE --accelerator=v100 --test=inference --report=histogram
DIFF v100.inference.histogram.test
RM v100.inference.histogram.test.tmp
AGGREGATE --accelerator=v100 --test=inference --report=latest
DIFF v100.inference.latest.test
RM v100.inference.latest.test.tmp
AGGREGATE --accelerator=v100 --test=inference --report=speedup
DIFF v100.inference.speedup.test
RM v100.inference.speedup.test.tmp
make: Leaving directory '/src/pytorch/xla/test/benchmarks'
$ test/benchmarks/run_tests.sh -L -V 1
[...]
+ make -C /src/pytorch/xla/test/benchmarks V=1 all
make: Entering directory '/src/pytorch/xla/test/benchmarks'
python3 ../../benchmarks/aggregate.py --accelerator=a6000 --test=inference --report=speedup \
--input-dirname=. --format=csv > a6000.inference.speedup.test.tmp
git diff --no-index a6000.inference.speedup.test a6000.inference.speedup.test.tmp
rm -f a6000.inference.speedup.test.tmp
python3 ../../benchmarks/aggregate.py --accelerator=v100 --test=inference --report=histogram \
--input-dirname=. --format=csv > v100.inference.histogram.test.tmp
git diff --no-index v100.inference.histogram.test v100.inference.histogram.test.tmp
rm -f v100.inference.histogram.test.tmp
python3 ../../benchmarks/aggregate.py --accelerator=v100 --test=inference --report=latest \
--input-dirname=. --format=csv > v100.inference.latest.test.tmp
git diff --no-index v100.inference.latest.test v100.inference.latest.test.tmp
rm -f v100.inference.latest.test.tmp
python3 ../../benchmarks/aggregate.py --accelerator=v100 --test=inference --report=speedup \
--input-dirname=. --format=csv > v100.inference.speedup.test.tmp
git diff --no-index v100.inference.speedup.test v100.inference.speedup.test.tmp
rm -f v100.inference.speedup.test.tmp
make: Leaving directory '/src/pytorch/xla/test/benchmarks'
```
