Strip whitespace from revision

[b-deam]

You can test this PR yourself (prior to elastic/rally#1772 being merged) by applying this patch to your local rally-tracks checkout:

diff --git a/pyproject.toml b/pyproject.toml
index fae550f..c1f6ba9 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -33,7 +33,8 @@ exclude = [
 [tool.hatch.envs.default]
 dependencies = [
     "esrally[develop] @ git+https://github.com/elastic/rally.git@master",
-    "pytest-rally @ git+https://github.com/elastic/pytest-rally.git@main",
+    "pytest-rally @ file:///home/esbench/pytest-rally",
+    #"pytest-rally @ git+https://github.com/elastic/pytest-rally.git@main",
 ]
 
 [tool.hatch.envs.unit]

And using this invocation:

$ /home/esbench/rally-tracks
$ pip cache remove pytest_rally && hatch env prune  && hatch -v -e it run test

Relates elastic/rally#1772

[pquentin]

Thanks! I've left optional suggestions.

[pquentin]

This strip() is not needed as branches was split over "\n" already. But I'm happy to be over-resilient here.