Robot Framework 7.0 changes

Update robot code syntax overall in the repo

Changes:
   - Update the requirement.txt package version for robot
   - The '[Return]' setting is deprecated.
      Use the 'RETURN' statement instead.
   - Singular section headers like '*** Test Case ***'
     are deprecated. Use plural format like
     '*** Test Cases ***' instead.
   - Singular section headers like '*** Variable ***'
     are deprecated

Tested:
   - Ran from sandbox with the version
     $ robot --version
     Robot Framework 7.0 (Python 3.10.12 on linux)

     and also tested on latest python version

     Robot Framework 7.0 (Python 3.11.9 on linux)

Change-Id: I54e85f9d799556c63b9a39f79483f83e9b980768
Signed-off-by: George Keishing <gkeishin@in.ibm.com>
diff --git a/redfish/systems/test_systems_inventory.robot b/redfish/systems/test_systems_inventory.robot
index 0ec05c8..c3e24e2 100755
--- a/redfish/systems/test_systems_inventory.robot
+++ b/redfish/systems/test_systems_inventory.robot
@@ -175,7 +175,7 @@
 
     ${total_cores}=  Redfish.Get Attribute  ${processor}  TotalCores
     Return From Keyword If  ${total_cores} is ${NONE}  ${0}
-    [Return]  ${total_cores}
+    RETURN  ${total_cores}
 
 
 GPU State Check
@@ -212,7 +212,7 @@
     ${power_supplies}=  Redfish.Get Attribute
     ...  ${REDFISH_CHASSIS_URI}${CHASSIS_ID}/Power  PowerSupplies
 
-    [Return]  ${cpu_info}  ${gpu_info}  ${power_supplies}
+    RETURN  ${cpu_info}  ${gpu_info}  ${power_supplies}
 
 
 Verify FRU Inventory Minimums