Prevent accidental canceling of tester runs

[gassmoeller]

Fix a mistake introduced in #561. Because benchmarks and tests had the same 'group' one of the two workflows would be cancelled if the other was running. Give them two different tags to distinguish between them.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (3c5e302) 93.55% compared to head (bf5a404) 93.55%.
Report is 4 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #566   +/-   ##
=======================================
  Coverage   93.55%   93.55%           
=======================================
  Files          92       92           
  Lines        6343     6343           
=======================================
  Hits         5934     5934           
  Misses        409      409           

---

Continue to review full report in Codecov by Sentry.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 3c5e302...bf5a404. Read the comment docs.

[github-actions]

Benchmark	Main	Feature	Difference (99.9% CI)
Slab interpolation simple none	1.025 ± 0.003 (s=416)	1.026 ± 0.003 (s=464)	-0.0% .. +0.1%
Slab interpolation curved simple none	1.028 ± 0.004 (s=442)	1.026 ± 0.003 (s=437)	-0.3% .. -0.2%
Spherical slab interpolation simple none	1.272 ± 0.008 (s=347)	1.271 ± 0.009 (s=363)	-0.2% .. +0.1%
Slab interpolation simple curved CMS	1.097 ± 0.003 (s=411)	1.099 ± 0.002 (s=411)	+0.1% .. +0.2%
Spherical slab interpolation simple CMS	1.863 ± 0.005 (s=237)	1.861 ± 0.006 (s=249)	-0.2% .. -0.0%
Spherical fault interpolation simple none	1.276 ± 0.004 (s=377)	1.274 ± 0.004 (s=331)	-0.3% .. -0.1%
Cartesian min max surface	2.390 ± 0.017 (s=188)	2.389 ± 0.021 (s=191)	-0.3% .. +0.2%
Spherical min max surface	7.391 ± 0.020 (s=63)	7.389 ± 0.016 (s=61)	-0.2% .. +0.1%