Update agent version in root context (#4112)

# Summary

This field in the root context is not updated automatically. The agent
version here was obsolete and should have been changed with this PR
10gen/ops-manager-kubernetes#3973.

Without this change, running the operator locally wouldn't work with MDB
8 deployments.

## Proof of Work

N/A

## Checklist
- [ ] Have you linked a jira ticket and/or is the ticket in the title?
- [ ] Have you checked whether your jira ticket required DOCSP changes?
- [ ] Have you checked for release_note changes?

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Author: lucian-tosa

scripts/dev/contexts/root-context

@@ -35,8 +35,8 @@ fi
 
 export OPERATOR_ENV=${OPERATOR_ENV:-"dev"}
 
-# provide a way to automatically source it from release.json/agentVersion
-export AGENT_VERSION="107.0.0.8502-1"
+AGENT_VERSION="$(jq -r '.agentVersion' release.json)"
+export AGENT_VERSION
 export AGENT_IMAGE="${MDB_AGENT_IMAGE_REPOSITORY}:${AGENT_VERSION}"
 
 # Ops Manager

scripts/dev/contexts/variables/om60

@@ -14,6 +14,7 @@ export CUSTOM_MDB_VERSION=6.0.16
 export CUSTOM_MDB_PREV_VERSION=5.0.7
 
 export AGENT_VERSION=12.0.33.7866-1
+export AGENT_IMAGE="${MDB_AGENT_IMAGE_REPOSITORY}:${AGENT_VERSION}"
 
 export CUSTOM_APPDB_VERSION=6.0.5-ent
 export TEST_MODE=opsmanager

scripts/dev/contexts/variables/om70

@@ -14,6 +14,7 @@ export CUSTOM_MDB_VERSION=7.0.2
 export CUSTOM_MDB_PREV_VERSION=6.0.5
 
 export AGENT_VERSION=107.0.11.8645-1
+export AGENT_IMAGE="${MDB_AGENT_IMAGE_REPOSITORY}:${AGENT_VERSION}"
 
 export CUSTOM_APPDB_VERSION=7.0.2-ent
 export TEST_MODE=opsmanager

scripts/dev/contexts/variables/om80

@@ -14,6 +14,7 @@ export CUSTOM_MDB_VERSION=8.0.0
 export CUSTOM_MDB_PREV_VERSION=7.0.9
 
 export AGENT_VERSION=108.0.0.8694-1
+export AGENT_IMAGE="${MDB_AGENT_IMAGE_REPOSITORY}:${AGENT_VERSION}"
 
 export CUSTOM_APPDB_VERSION=8.0.0-ent
 export TEST_MODE=opsmanager