chore: configure Codecov to include only relevant directories for coverage (operator-framework#1431)

- Updated .codecov.yml to include only specific directories (api/, cmd/, internal/) in coverage reports
- Excluded documentation, YAML configurations, and test files to improve coverage accuracy and prevent irrelevant CI coverage failures

Author: camilamacedo86

Diff for: codecov.yml

@@ -1,3 +1,11 @@
 codecov:
   notify:
     after_n_builds: 2
+
+# Configure the paths to include in coverage reports.
+# Exclude documentation, YAML configurations, and test files.
+coverage:
+  paths:
+    - "api/"
+    - "cmd/"
+    - "internal/"