Create Terraform resource for Azure Container App Job for runner

[bcspragu]

PR #123 changes how we trigger jobs to start them based on an existing template, called 'pacta-runner'. This was created manually in local, dev, because the Terraform Azure provider doesn't current support jobs, but support is literally being merged as we speak, so I expect this will be a fast follow

Rough params to set:

rg: rmi-pacta-<env>
job-name: pacta-runner-<env>
container-apps-env: pacta-<env>
trigger: manual
image: runner
tag: 'latest' for local, <env> for all others
resources: 1 vCPU, 2 GiB RAM

user-assigned managed-identity of pacta-runner-<env>

local env vars
AZURE_CLIENT_ID c02b7346-6ba6-438a-8136-1ccb608e5449
MANAGED_IDENTITY_CLIENT_ID c02b7346-6ba6-438a-8136-1ccb608e5449

dev env vars
AZURE_CLIENT_ID fe1d8f9a-2806-4c9a-ba20-1dcf63ee3e27
MANAGED_IDENTITY_CLIENT_ID fe1d8f9a-2806-4c9a-ba20-1dcf63ee3e27