add pr tag to coverage report

Author: blink1073

.evergreen/generated_configs/tasks.yml

@@ -134,7 +134,7 @@ tasks:
     commands:
       - func: download and merge coverage
     depends_on: [{ name: .server-version, variant: .coverage_tag, status: "*", patch_optional: true }]
-    tags: [coverage]
+    tags: [coverage, pr]
 
   # Free threading tests
   - name: test-free-threading

.evergreen/scripts/generate_config.py

@@ -860,7 +860,7 @@ def create_getdata_tasks():
 
 
 def create_coverage_report_tasks():
-    tags = ["coverage"]
+    tags = ["coverage", "pr"]
     task_name = "coverage-report"
     # BUILD-3165: We can't use "*" (all tasks) and specify "variant".
     # Instead list out all coverage tasks using tags.