Fix error when not in git repo

[szh]

Desired Outcome

When using bash-lib outside of a git repository, the init script is failing when it tries to update any git submodules (which is intended to update bash-lib itself when being used as a submodule).

Implemented Changes

• init script ignores any errors generated by the git submodule update command.

Connected Issue/Story

N/A

Changelog

• [ ] The CHANGELOG has been updated, or
• [ ] This PR does not include user-facing changes and doesn't require a CHANGELOG update

Test coverage

• [ ] This PR includes new unit and integration tests to go with the code changes, or
• [ ] The changes in this PR do not require tests

Documentation

• [ ] Docs (e.g. READMEs) were updated in this PR
• [ ] A follow-up issue to update official docs has been filed here: insert issue ID
• [x] This PR does not require updating any documentation

Behavior

• [ ] This PR changes product behavior and has been reviewed by a PO, or
• [ ] These changes are part of a larger initiative that will be reviewed later, or
• [x] No behavior was changed with this PR

Security

• [ ] Security architect has reviewed the changes in this PR,
• [ ] These changes are part of a larger initiative with a separate security review, or
• [x] There are no security aspects to these changes