Deprioritized rad terraform install in feature spec

[zachcasper]

There are no material changes in this PR other than reprioritizing. rad terraform install is moved to p3.

The summary of changes table used to look like:

Priority	Size	Description
p0	L	New rad terraform install command with URL and checksum; removal of dynamic Terraform installation
p1	M	Setting the Terraform CLI configuration based on the new TerraformSettings resource
p1	M	azurerm backend type in TerraformSettings; service principal and managed identity authentication from Radius credentials
p1	S	Support for TF_LOG and TF_LOG_PATH
p2	M	s3 backend type in TerraformSettings; access key authentication from Radius credentials
p3	M	kubernetes backend type in TerraformSettings (same functionality as today but customizable)
p3	M	New rad terraform uninstall command

Now it looks like:

Priority	Size	Description
p1	M	Setting the Terraform CLI configuration based on the new TerraformSettings resource
p1	M	azurerm backend type in TerraformSettings; service principal and managed identity authentication from Radius credentials
p1	M	s3 backend type in TerraformSettings; access key authentication from Radius credentials
p1	M	kubernetes backend type in TerraformSettings (same functionality as today but customizable)
p1	M	Setting the Bicep configuration based on the new BicepSettings resource
p2	S	Support for TF_LOG and TF_LOG_PATH
p3	L	New rad terraform install command with URL and checksum; removal of dynamic Terraform installation
p3	M	New rad terraform uninstall command