Resource version updates (#204)

## Purpose
Update Bicep resource versions
## Does this introduce a breaking change?
<!-- Mark one with an "x". -->
```
[ ] Yes
[x] No
```

## Pull Request Type
What kind of change does this Pull Request introduce?

<!-- Please check the one that applies to this PR using "x". -->
```
[ ] Bugfix
[ ] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[x] Documentation content changes
[ ] Other... Please describe:
```

Author: dominicbetts

samples/custom-connector-bicep/connector-verify.bicep

@@ -32,15 +32,15 @@ resource aioExtension 'Microsoft.KubernetesConfiguration/extensions@2022-11-01'
   scope: connectedCluster
 }
 
-resource aioInstance 'Microsoft.IoTOperations/instances@2026-07-01' existing = {
+resource aioInstance 'Microsoft.IoTOperations/instances@2026-03-01' existing = {
   name: aioInstanceName
 }
 
-resource defaultDataflowEndpoint 'Microsoft.IoTOperations/instances/dataflowEndpoints@2026-07-01' existing = {
+resource defaultDataflowEndpoint 'Microsoft.IoTOperations/instances/dataflowEndpoints@2026-03-01' existing = {
   name: defaultDataflowEndpointName
 }
 
-resource defaultDataflowProfile 'Microsoft.IoTOperations/instances/dataflowProfiles@2026-07-01' existing = {
+resource defaultDataflowProfile 'Microsoft.IoTOperations/instances/dataflowProfiles@2026-03-01' existing = {
   name: defaultDataflowProfileName
   parent: aioInstance
 }
@@ -88,7 +88,7 @@ resource eventHub 'Microsoft.EventHub/namespaces/eventhubs@2024-01-01' = {
 /*                                    Data flow                              */
 /*****************************************************************************/
 
-resource dataflowEndpointEventHub 'Microsoft.IoTOperations/instances/dataflowEndpoints@2026-07-01' = {
+resource dataflowEndpointEventHub 'Microsoft.IoTOperations/instances/dataflowEndpoints@2026-03-01' = {
   parent: aioInstance
   name: 'thermostat-eh-endpoint'
   extendedLocation: {
@@ -119,7 +119,7 @@ resource dataflowEndpointEventHub 'Microsoft.IoTOperations/instances/dataflowEnd
   ]
 }
 
-resource dataflowThermostat 'Microsoft.IoTOperations/instances/dataflowProfiles/dataflows@2026-07-01' = {
+resource dataflowThermostat 'Microsoft.IoTOperations/instances/dataflowProfiles/dataflows@2026-03-01' = {
   parent: defaultDataflowProfile
   name: 'thermostat-data-flow'
   extendedLocation: {

samples/quickstarts/quickstart.bicep

@@ -32,15 +32,15 @@ resource aioExtension 'Microsoft.KubernetesConfiguration/extensions@2022-11-01'
   scope: connectedCluster
 }
 
-resource aioInstance 'Microsoft.IoTOperations/instances@2026-07-01' existing = {
+resource aioInstance 'Microsoft.IoTOperations/instances@2026-03-01' existing = {
   name: aioInstanceName
 }
 
-resource defaultDataflowEndpoint 'Microsoft.IoTOperations/instances/dataflowEndpoints@2026-07-01' existing = {
+resource defaultDataflowEndpoint 'Microsoft.IoTOperations/instances/dataflowEndpoints@2026-03-01' existing = {
   name: defaultDataflowEndpointName
 }
 
-resource defaultDataflowProfile 'Microsoft.IoTOperations/instances/dataflowProfiles@2026-07-01' existing = {
+resource defaultDataflowProfile 'Microsoft.IoTOperations/instances/dataflowProfiles@2026-03-01' existing = {
   name: defaultDataflowProfileName
   parent: aioInstance
 }