tfexec: enable -lock and -lock-timeout Init flags for >=1.0.10

[sbocinec]

Related Issue

Fixes #229

Description

Allow using -lock and -lock-timeout flags on init command for Terraform versions >=0.15, <1.0.10. As reported in #229, these flags were restored in 1.0.10 so using these flags in recent versions of terraform is throwing an error.

Rollback Plan

• If a change needs to be reverted, we will roll out an update to the code within 7 days.

Changes to Security Controls

• n-a