Update Codecov configuration to enable annotations and improve stability

.codecov.yml

@@ -1,26 +1,26 @@
-# the comments are too noisy to be useful
+# The comments are too noisy to be useful
 comment: false
 
-# disable noisy inline-annotations ("Added line [LineNum] was not covered by tests") on PRs (#8296)
+# Enable annotations on PRs to get detailed feedback on coverage
 # https://docs.codecov.io/docs/github-checks-beta
 github_checks:
-  annotations: false
+  annotations: true  # Annotations enabled to review fluctuation issues
 
 coverage:
   range: "36...100"
   status:
     project:
       default:
-        # dropping slightly is ok - this stops the check failing on test timing variability
-        # .12 was observed as the largest variability owing to timing forcing different test branch choice
+        # Dropping slightly is ok - this stops the check failing on test timing variability
+        # 0.12 was observed as the largest variability owing to timing forcing different test branch choice
         threshold: 0.15
-        # BUG: our coverage fluctuates, so codecov marks this as a build failure (#12227)
-        # stop codecov from failing CI until this is fixed
+        # BUG: our coverage fluctuates, so Codecov marks this as a build failure (#12227)
+        # Stop Codecov from failing CI until this is fixed
         # https://docs.codecov.com/docs/commit-status#informational
         informational: true
     patch:
       default:
-        # BUG: our coverage fluctuates, so codecov marks this as a build failure (#12227)
-        # stop codecov from failing CI until this is fixed
+        # BUG: our coverage fluctuates, so Codecov marks this as a build failure (#12227)
+        # Stop Codecov from failing CI until this is fixed
         # https://docs.codecov.com/docs/commit-status#informational
-        informational: true
+        informational: true