Update codecov.yml (antrea-io#4226)

1. Codecov do not comment until at least 5 builds have been uploaded
from the CI pipeline. By default codecov will post and/or update the
pull request comment after it processes each report uploaded for a
particular pull request commit. As the Antrea CI process uploads many
reports to codecov, this can be confusing for team members viewing the
pull request as reports are processing.
2. patch/status ensures the patch lines cov > 65%(ut or e2e/integration).
3. project/status ensures the project ut cov not decrease.
4. Set carryforward: false, as the Carryforward Flags are designed for
projects that do not upload total coverage for every commit.

Signed-off-by: Wenqi Qiu <wenqiq@vmware.com>

codecov.yaml

@@ -1,53 +1,48 @@
 codecov:
+  # The default branch is used to identify:
+  #  Which branch to cache the repository YAML for UI changes.
+  #  Which branch is the first branch on the repository dashboard in Codecov.
   branch: main
+  # Show the Codecov status without waiting for other status checks to complete or pass.
   require_ci_to_pass: no
 
-comment:
-  layout: "reach,diff,flags,tree"
-  behavior: default
-  require_changes: no
-  require_base: no
-  require_head: no
-  after_n_builds: 1
-  show_carryforward_flags: true
+comment: false
 
 github_checks:
+  # Specify whether to use GitHub Checks annotations or normal statuses.
   annotations: true
 
 coverage:
   status:
     patch:
       default:
+        # Choose a minimum coverage ratio that the commit must meet to be considered a success.
+        # <number> specify a target of an exact coverage number.
         target: 70%
+        # Allow the coverage to drop by X%, and posting a success status.
         threshold: 5%
+        # Use the pull request base if the commit is on a pull request. If not, the parent commit will be used.
         base: auto
+        # Only post a status to pull requests.
         only_pulls: true
         flags:
           - unit-tests
     project:
       default:
+        # `auto` will use the coverage from the base commit (pull request base or parent commit) coverage to compare against.
         target: auto
       antrea-unit-tests:
         target: auto
+        # Flags are a list of user defined Flags, and the impact on their coverage.
         flags:
           - unit-tests
-      antrea-integration-tests:
-        target: auto
-        flags:
-          - integration-tests
-      antrea-e2e-tests:
-        target: auto
-        flags:
-          - e2e-tests
-      antrea-kind-e2e-tests:
-        target: auto
-        flags:
-          - kind-e2e-tests
+
 
 flag_management:
   default_rules:
     carryforward: true
 
+# Exclude files from being collected by Codecov. Ignored files will be skipped during processing.
 ignore:
   - "**/testing/*.go"
   - "**/mock_*.go"