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/lib/dmtf_redfishtool_utils.robot b/lib/dmtf_redfishtool_utils.robot
index 089bab3..caf7f31 100644
--- a/lib/dmtf_redfishtool_utils.robot
+++ b/lib/dmtf_redfishtool_utils.robot
@@ -27,7 +27,7 @@
     ${rc}  ${cmd_output}=  Run and Return RC and Output  ${cmd}
     Run Keyword If  ${rc} != 0  Is HTTP error Expected  ${cmd_output}  ${expected_error}
 
-    [Return]  ${cmd_output}
+    RETURN  ${cmd_output}
 
 
 Redfishtool Patch
@@ -46,7 +46,7 @@
     ${rc}  ${cmd_output}=  Run and Return RC and Output  ${cmd}
     Run Keyword If  ${rc} != 0  Is HTTP error Expected  ${cmd_output}  ${expected_error}
 
-    [Return]  ${cmd_output}
+    RETURN  ${cmd_output}
 
 
 Redfishtool Post
@@ -66,7 +66,7 @@
     ${rc}  ${cmd_output}=  Run and Return RC and Output  ${cmd}
     Run Keyword If  ${rc} != 0  Is HTTP error Expected  ${cmd_output}  ${expected_error}
 
-    [Return]  ${cmd_output}
+    RETURN  ${cmd_output}
 
 
 Redfishtool Delete
@@ -84,7 +84,7 @@
     ${rc}  ${cmd_output}=  Run and Return RC and Output  ${cmd}
     Run Keyword If  ${rc} != 0  Is HTTP error Expected  ${cmd_output}  ${expected_error}
 
-    [Return]  ${cmd_output}
+    RETURN  ${cmd_output}
 
 
 Is HTTP error Expected