Add dependabot-generate make target

[MrAlias]

Fix #2612

• A new dependabot-generate target is added to automatically and reproducible generate the dependabot configuration. This is added as a way to easy fixing the error generated by dependabot-check. This target is added to the precommit target dependencies.
• A dedicated dbotconf utility is added to generate the dependabot configuration.
• The common code used between crosslink and dbotconf is refactored into the tools package.
• The dependabot configuration is updated to be generated with this new target.

[codecov]

Codecov Report

Merging #2613 (631f24a) into main (67f508b) will increase coverage by 0.0%.
The diff coverage is n/a.

@@          Coverage Diff          @@
##            main   #2613   +/-   ##
=====================================
  Coverage   76.1%   76.2%           
=====================================
  Files        173     173           
  Lines      12234   12234           
=====================================
+ Hits        9320    9327    +7     
+ Misses      2671    2666    -5     
+ Partials     243     241    -2     

Impacted Files	Coverage Δ
exporters/jaeger/jaeger.go	92.6% <0.0%> (-0.9%)	⬇️
sdk/trace/batch_span_processor.go	81.1% <0.0%> (+0.9%)	⬆️
sdk/metric/sdk.go	81.5% <0.0%> (+1.4%)	⬆️
sdk/metric/refcount_mapped.go	100.0% <0.0%> (+20.0%)	⬆️

[dmathieu]

How about a check that would fail if an auto-generated file becomes out of sync from the generator?
(it may be better as a separated PR)

[pellared]

How about a check that would fail if an auto-generated file becomes out of sync from the generator? (it may be better as a separated PR)

I agree. It should be enough to add dependabot-generate as a dependency to the ci target. The check-clean-work-tree target should catch if any file gets modified.