Allow custom command execution before install

[pdebakker-auguria]

Is there an existing issue for this?

• I have searched the existing issues

Feature description

We currently use protobuf which gets compiled from the .proto files into (in our case) .pb.go files.
Because we don't want to clutter our VCS with the changes in these auto generated code files, we only store the .proto files in git.

But, when dependabot tries to update our go modules and run go install to check for conflicts, this won't work.

This is a small snippet from the resulting logs, starting when we see the first error.
I could also send the full log file, but I don't want to clutter.

  proxy | 2024/04/30 11:20:51 [291] 200 https://proxy.golang.org:443/gopkg.in/yaml.v2/@v/v2.4.0.info
  proxy | 2024/04/30 11:20:51 [293] GET https://proxy.golang.org:443/github.com/stretchr/testify/@v/v1.8.4.zip
  proxy | 2024/04/30 11:20:51 [293] 200 https://proxy.golang.org:443/github.com/stretchr/testify/@v/v1.8.4.zip
updater | 2024/04/30 11:20:52 ERROR <job_821671931> Error processing github.com/xitongsys/parquet-go (Dependabot::DependabotError)
updater | 2024/04/30 11:20:52 ERROR <job_821671931> go: downloading google.golang.org/protobuf v1.33.0
updater | go: downloading github.com/golang/protobuf v1.5.0
updater | go: downloading github.com/olekukonko/tablewriter v0.0.5
updater | go: downloading github.com/segmentio/encoding v0.4.0
updater | go: downloading github.com/andybalholm/brotli v1.1.0
updater | go: auguria-pipeline imports
updater | 	auguria-pipeline/lib/storage imports
updater | 	auguria-pipeline/auguria_pb: package auguria-pipeline/auguria_pb is not in std (/opt/go/src/auguria-pipeline/auguria_pb)
updater | go: downloading github.com/stretchr/testify v1.8.4
updater | go: module github.com/golang/protobuf is deprecated: Use the "google.golang.org/protobuf" module instead.
updater | 2024/04/30 11:20:52 ERROR <job_821671931> /home/dependabot/go_modules/lib/dependabot/go_modules/file_updater/go_mod_updater.rb:328:in `handle_subprocess_error'
updater | 2024/04/30 11:20:52 ERROR <job_821671931> /home/dependabot/dependabot-updater/vendor/ruby/3.1.0/gems/sorbet-runtime-0.5.11353/lib/types/private/methods/call_validation.rb:270:in `bind_call'
updater | 2024/04/30 11:20:52 ERROR <job_821671931> /home/dependabot/dependabot-updater/vendor/ruby/3.1.0/gems/sorbet-runtime-0.5.11353/lib/types/private/methods/call_validation.rb:270:in `validate_call'
updater | 2024/04/30 11:20:52 ERROR <job_821671931> /home/dependabot/dependabot-updater/vendor/ruby/3.1.0/gems/sorbet-runtime-0.5.11353/lib/types/private/methods/_methods.rb:277:in `block in _on_method_added'
updater | 2024/04/30 11:20:52 ERROR <job_821671931> /home/dependabot/go_modules/lib/dependabot/go_modules/file_updater/go_mod_updater.rb:234:in `run_go_get'
updater | 2024/04/30 11:20:52 ERROR <job_821671931> /home/dependabot/dependabot-updater/vendor/ruby/3.1.0/gems/sorbet-runtime-0.5.11353/lib/types/private/methods/call_validation.rb:167:in `bind_call'
updater | 2024/04/30 11:20:52 ERROR <job_821671931> /home/dependabot/dependabot-updater/vendor/ruby/3.1.0/gems/sorbet-runtime-0.5.11353/lib/types/private/methods/call_validation.rb:167:in `validate_call_skip_block_type'
updater | 2024/04/30 11:20:52 ERROR <job_821671931> /home/dependabot/dependabot-updater/vendor/ruby/3.1.0/gems/sorbet-runtime-0.5.11353/lib/types/private/methods/call_validation.rb:109:in `block in create_validator_slow_skip_block_type'
updater | 2024/04/30 11:20:52 ERROR <job_821671931>