Lower the time tests take to run

[another-rex]

Our go tests are starting to take quite a long time now, we should look into performance improvements or gating tests behind flags so they are not always ran. (though caching should already be doing this)

Here are the tests that are currently taking more than 2 seconds, sorted in ascending order:

TestRun_MavenTransitive/scans_transitive_dependencies_by_specifying_pom.xml,2.04
TestRun_MavenTransitive/scans_transitive_dependencies_for_pom.xml_by_default,2.35
TestRun/config_file_can_be_broad,2.38
TestRun_Licenses/No_vulnerabilities_with_license_summary_in_markdown,2.42
TestRun_MavenTransitive/scans_dependencies_from_multiple_registries,2.52
TestRun/PURL_SBOM_case_sensitivity_(local),2.52
TestRun_MavenTransitive/resolve_transitive_dependencies_with_native_data_source,2.6
TestRun_Licenses/Some_packages_with_ignored_licenses,2.7
Test_runGovulncheck,2.9
TestRun/requirements.txt_can_have_all_kinds_of_names,2.97
TestRun_LocalDatabases/only_the_files_in_the_given_directories_are_checked_by_default_(no_recursion),3.39
TestRun_LocalDatabases/.gitignored_files,3.91
TestRun_LocalDatabases/all_supported_lockfiles_in_the_directory_should_be_checked#01,3.97
TestRun_LocalDatabases/nested_directories_are_checked_when_`--recursive`_is_passed,4.53
TestRun_Fix/fix_non-interactive_json_override_pom.xml,4.54
TestRun_Fix/fix_non-interactive_override_pom.xml,4.67
TestPrintCycloneDX14Results_WithVulnerabilities,4.87
TestPrintCycloneDX15Results_WithLicenseViolations,4.95
TestPrintOutputResults_WithVulnerabilities,4.96
TestFromCSVFile,5.05
TestRun_LocalDatabases/ignoring_.gitignore,5.08
TestRunCallAnalysis/Run_with_govulncheck,5.42
TestPrintTableResults_NoTerminalWidth_WithVulnerabilities,6.05
TestCVE202230633,6.12
TestRun/folder_of_supported_sbom_with_vulns,7.27
TestRun_Fix/fix_non-interactive_relax_package.json,8.87
TestRun_LocalDatabases/all_supported_lockfiles_in_the_directory_should_be_checked,9.46
TestRun_Fix/fix_non-interactive_json_relax_package.json,9.61
TestRun_Fix/fix_non-interactive_json_in-place_package-lock.json,10.18
TestRun_Fix/fix_non-interactive_in-place_package-lock.json,11.06
TestRun_LocalDatabases/one_specific_supported_sbom_with_vulns,22.01

[G-Rath]

(though caching should already be doing this)

Sadly caching doesn't tend to help because our top-most packages by definition depend on everything meaning 1. they're generally the slowest of tests as they're the most e2e-y, and 2. pretty much all changes to the codebase invalid their test cache

[G-Rath]

So I knew since we introduced them that the offline/local database based tests are a large source of time because they have to download the all.zip files multiple times and they can be quite large - I've had an idea or two on how we could possibly improve this which I'm exploring now and it looks like it's working (taking us down to 10 seconds!).

There's some trade-offs to discuss and I need to actually cleanup the code to confirm everything properly which is why I'm not sharing more details just yet, but mentioning it now in case anyone else looks at this to avoid possible double work