Use fetch-depth 0 to make minver work properly

[alanwest]

CI is failing on #3408 with the following:

CSC : error CS1705: Assembly 'OpenTelemetry.Instrumentation.Runtime' with identity 'OpenTelemetry.Instrumentation.Runtime, Version=1.0.0.1, Culture=neutral, PublicKeyToken=7bd6737fe5b67e3c' uses 'OpenTelemetry.Api, Version=1.0.0.0, Culture=neutral, PublicKeyToken=7bd6737fe5b67e3c' which has a higher version than referenced assembly 'OpenTelemetry.Api' with identity 'OpenTelemetry.Api, Version=0.0.0.0, Culture=neutral, PublicKeyToken=7bd6737fe5b67e3c' [/home/runner/work/opentelemetry-dotnet/opentelemetry-dotnet/examples/AspNetCore/Examples.AspNetCore.csproj]

This is because minver does not actually version our assemblies for PR builds and builds triggered for pushes to main. For minver to work, we need to set fetch-depth=0.

I suspect this may have some impact on build times... not sure what the overhead of fetching all commits is.

[codecov]

Codecov Report

Merging #3412 (2a63e23) into main (34efdbf) will increase coverage by 0.02%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main    #3412      +/-   ##
==========================================
+ Coverage   86.28%   86.30%   +0.02%     
==========================================
  Files         258      258              
  Lines        9269     9269              
==========================================
+ Hits         7998     8000       +2     
+ Misses       1271     1269       -2     

Impacted Files	Coverage Δ
...ter.ZPages/Implementation/ZPagesActivityTracker.cs	100.00% <0.00%> (+2.85%)	⬆️
...ZPages/Implementation/ZPagesExporterEventSource.cs	62.50% <0.00%> (+6.25%)	⬆️