bump nim-libbacktrace to `b6e26f03c091a8e3bba6adc06198fc3055bacc66`

[etan-status]

• bump libbacktrace to 86885d14049fab06ef8a33aac51664230ca09200
• bump whereami to dcb52a058dc14530ba9ae05e4339bd3ddfae0e0e

[github-actions[bot]]

Unit Test Results

         9 files  ±0    1 337 suites  ±0   46m 2s :stopwatch: + 2m 11s   5 066 tests ±0    4 718 :heavy_check_mark: ±0  348 :zzz: ±0  0 :x: ±0  20 997 runs  ±0  20 593 :heavy_check_mark: ±0  404 :zzz: ±0  0 :x: ±0 

Results for commit 2215e5de. ± Comparison against base commit 73be2af0.