GONRG-5583 fix add required version for tf

File df-tf-ci-check.yml

• Added new variable OSDU_GCP_DF_TF_CI_TF_VERSION
• Replaced hardcoded version of Terraform in pipeline with the new variable

File simple_osdu/Readme.md

• Updated the required Terraform version to new value

File main.tf

• Added Terraform version constraint