PYTHON-5879 Use distinct tag for non-coverage companion tasks to avoid selector leakage

Companion tasks previously carried the "test-non-standard" tag, which caused
selectors in other variants (load-balancer, PyOpenSSL, standalone-noauth-nossl)
to accidentally match them and run duplicate tasks.

Fix: companions now use "test-non-standard-no-cov" as their primary tag instead
of "test-non-standard". The macOS/Win64 encryption variant selectors are updated
to explicitly include ".test-non-standard-no-cov !.pypy" alongside the existing
".test-non-standard !.pypy !.cov" selector.

Author: aclark4life

.evergreen/generated_configs/tasks.yml

@@ -4844,7 +4844,7 @@ tasks:
           VERSION: latest
           TOOLCHAIN_VERSION: 3.14t
     tags:
-      - test-non-standard
+      - test-non-standard-no-cov
       - server-latest
       - python-3.14t
       - replica_set-noauth-ssl
@@ -4914,7 +4914,7 @@ tasks:
           VERSION: latest
           TOOLCHAIN_VERSION: "3.14"
     tags:
-      - test-non-standard
+      - test-non-standard-no-cov
       - server-latest
       - python-3.14
       - sharded_cluster-auth-ssl
@@ -4961,7 +4961,7 @@ tasks:
           VERSION: latest
           TOOLCHAIN_VERSION: "3.13"
     tags:
-      - test-non-standard
+      - test-non-standard-no-cov
       - server-latest
       - python-3.13
       - standalone-noauth-nossl

.evergreen/generated_configs/variants.yml

@@ -194,6 +194,7 @@ buildvariants:
   - name: encryption-macos
     tasks:
       - name: .test-non-standard !.pypy !.cov
+      - name: .test-non-standard-no-cov !.pypy
     display_name: Encryption macOS
     run_on:
       - macos-14
@@ -204,6 +205,7 @@ buildvariants:
   - name: encryption-win64
     tasks:
       - name: .test-non-standard !.pypy !.cov
+      - name: .test-non-standard-no-cov !.pypy
     display_name: Encryption Win64
     run_on:
       - windows-2022-latest-small
@@ -225,6 +227,7 @@ buildvariants:
   - name: encryption-crypt_shared-macos
     tasks:
       - name: .test-non-standard !.pypy !.cov
+      - name: .test-non-standard-no-cov !.pypy
     display_name: Encryption crypt_shared macOS
     run_on:
       - macos-14
@@ -236,6 +239,7 @@ buildvariants:
   - name: encryption-crypt_shared-win64
     tasks:
       - name: .test-non-standard !.pypy !.cov
+      - name: .test-non-standard-no-cov !.pypy
     display_name: Encryption crypt_shared Win64
     run_on:
       - windows-2022-latest-small

.evergreen/scripts/generate_config.py

@@ -134,7 +134,9 @@ def get_encryption_expansions(encryption):
         if host != "rhel8":
             # Exclude PyPy (no Evergreen toolchain on macOS/win64) and coverage tasks
             # (encryption suites exceed the 60-min timeout with coverage overhead on macOS/win64).
-            tasks = [".test-non-standard !.pypy !.cov"]
+            # Also include the non-coverage companion tasks (test-non-standard-no-cov) which
+            # carry the "latest" server tasks without COVERAGE=1.
+            tasks = [".test-non-standard !.pypy !.cov", ".test-non-standard-no-cov !.pypy"]
         variant = create_variant(
             tasks,
             display_name,
@@ -684,7 +686,13 @@ def create_test_non_standard_tasks():
         # constraints) still have a "latest" task to activate in patch builds.
         if pr and "cov" in tags:
             nc_expansions = {k: v for k, v in expansions.items() if k != "COVERAGE"}
-            nc_tags = [t for t in tags if t != "cov"]
+            # Use a distinct primary tag so companions are not selected by existing
+            # ".test-non-standard" selectors (e.g. load-balancer, PyOpenSSL variants).
+            nc_tags = [
+                "test-non-standard-no-cov" if t == "test-non-standard" else t
+                for t in tags
+                if t != "cov"
+            ]
             nc_name = get_task_name("test-non-standard", python=python, **nc_expansions)
             nc_server_func = FunctionCall(func="run server", vars=nc_expansions)
             nc_test_vars = nc_expansions.copy()