codeintel: Handle unknown commits when recalculating commit graph for a repository

Created by: efritz

This should fix the issue described in https://github.com/sourcegraph/sourcegraph/issues/16837.

Created by: codecov[bot]

Codecov Report

Merging #16844 (537836a) into main (eaaaca4) will increase coverage by 5.70%. The diff coverage is 78.37%.

@@            Coverage Diff             @@
##             main   #16844      +/-   ##
==========================================
+ Coverage   46.78%   52.48%   +5.70%     
==========================================
  Files        1701     1701              
  Lines       84643    84635       -8     
  Branches     7663     7711      +48     
==========================================
+ Hits        39599    44422    +4823     
+ Misses      41143    36311    -4832     
- Partials     3901     3902       +1     

Flag	Coverage Δ		*Carryforward flag
go	51.69% <78.37%> (-0.01%)
integration	29.64% <ø> (?)		Carriedforward from a8a75be
storybook	28.76% <ø> (?)		Carriedforward from a8a75be
typescript	54.38% <ø> (+19.35%)		Carriedforward from a8a75be
unit	35.00% <ø> (-0.03%)		Carriedforward from a8a75be

*This pull request uses carry forward flags. Click here to find out more.

Impacted Files	Coverage Δ
...erprise/internal/codeintel/stores/dbstore/dumps.go	93.22% <ø> (-0.58%)
...ternal/codeintel/background/commitgraph/updater.go	63.07% <73.33%> (+2.69%)
...prise/internal/codeintel/stores/dbstore/uploads.go	90.77% <100.00%> (+0.17%)
.../enterprise/code-monitoring/CodeMonitoringNode.tsx	80.76% <0.00%> (-3.85%)
.../internal/codeintel/resolvers/graphql/locations.go	83.50% <0.00%> (ø)
client/web/src/search/helpers.tsx	93.10% <0.00%> (+0.86%)
...anded/src/components/panel/views/FileLocations.tsx	82.69% <0.00%> (+1.92%)
client/shared/src/util/url.ts	88.78% <0.00%> (+1.95%)
client/shared/src/components/FileMatchContext.ts	91.48% <0.00%> (+2.12%)
client/web/src/org/area/OrgInvitationPage.tsx	2.27% <0.00%> (+2.27%)
... and 343 more