[ANE-1009] golang retract statement

[meghfossa]

Overview

This PR,

• updates go.mod parser so, we don't fail when retract block exists

Acceptance criteria

• go.mod parser does not fail when, retract block exists

Testing plan

Prereq

git checkout master && git pull origin && git checkout go-lang-parser
make install-dev
mkdir sandbox && cd sandbox && wget https://raw.githubusercontent.com/open-telemetry/opentelemetry-collector-contrib/d1bda6802bc94c9c6980e9d47265801b4c62458f/internal/aws/xray/go.mod

Current

fossa analyze --output # fails

With Change

fossa-dev analyze --output # passes

Risks

N/A

References

https://fossa.atlassian.net/browse/ANE-1009

Checklist

• I added tests for this PR's change (or explained in the PR description why tests don't make sense).
• If this PR introduced a user-visible change, I added documentation into docs/.
• If this change is externally visible, I updated Changelog.md. If this PR did not mark a release, I added my changes into an # Unreleased section at the top.
• If I made changes to .fossa.yml or fossa-deps.{json.yml}, I updated docs/references/files/*.schema.json. You may also need to update these if you have added/removed new dependency type (e.g. pip) or analysis target type (e.g. poetry).

[zlav]

Looks great! Very thorough testing 🙌