PYTHON-5243 Migrate remaining variants to generated config

.evergreen/config.yml

@@ -350,37 +350,3 @@ tasks:
             - mongodb
             - mongo-python-driver
             - ${github_commit}
-
-buildvariants:
-
-- name: "Coverage Report"
-  display_name: "Coverage Report"
-  run_on:
-    - rhel84-small
-  tasks:
-     - name: "coverage-report"
-
-- name: testkms-variant
-  display_name: "KMS"
-  run_on:
-    - debian11-small
-  tasks:
-    - name: test-gcpkms
-      batchtime: 10080  # 7 days
-    - name: test-gcpkms-fail
-    - name: test-azurekms
-      batchtime: 10080  # 7 days
-    - name: test-azurekms-fail
-
-- name: rhel8-import-time
-  display_name: Import Time
-  run_on: rhel87-small
-  tasks:
-    - name: "check-import-time"
-
-- name: backport-pr
-  display_name: "Backport PR"
-  run_on:
-    - rhel8.7-small
-  tasks:
-    - name: "backport-pr"

.evergreen/generated_configs/variants.yml

@@ -151,6 +151,14 @@ buildvariants:
     run_on:
       - rhel87-small
 
+  # Backport pr tests
+  - name: backport-pr
+    tasks:
+      - name: backport-pr
+    display_name: Backport PR
+    run_on:
+      - rhel87-small
+
   # Compression tests
   - name: compression-snappy-rhel8-python3.9-no-c
     tasks:
@@ -237,6 +245,14 @@ buildvariants:
       COMPRESSORS: zstd
       PYTHON_BINARY: /opt/python/pypy3.10/bin/python3
 
+  # Coverage report tests
+  - name: coverage-report
+    tasks:
+      - name: coverage-report
+    display_name: Coverage Report
+    run_on:
+      - rhel87-small
+
   # Disable test commands tests
   - name: disable-test-commands-rhel8-python3.9
     tasks:
@@ -598,6 +614,27 @@ buildvariants:
       SSL: ssl
       PYTHON_BINARY: /opt/python/3.13/bin/python3
 
+  # Import time tests
+  - name: import-time
+    tasks:
+      - name: check-import-time
+    display_name: Import Time
+    run_on:
+      - rhel87-small
+
+  # Kms tests
+  - name: kms
+    tasks:
+      - name: test-gcpkms
+        batchtime: 10080
+      - name: test-gcpkms-fail
+      - name: test-azurekms
+        batchtime: 10080
+      - name: test-azurekms-fail
+    display_name: KMS
+    run_on:
+      - debian11-small
+
   # Load balancer tests
   - name: load-balancer
     tasks:

.evergreen/scripts/generate_config.py

@@ -62,6 +62,7 @@ class Host:
 HOSTS["ubuntu22"] = Host("ubuntu22", "ubuntu2204-small", "Ubuntu-22", dict())
 HOSTS["rhel7"] = Host("rhel7", "rhel79-small", "RHEL7", dict())
 HOSTS["perf"] = Host("perf", "rhel90-dbx-perf-large", "", dict())
+HOSTS["debian11"] = Host("debian11", "debian11-small", "Debian11", dict())
 DEFAULT_HOST = HOSTS["rhel8"]
 
 # Other hosts
@@ -85,7 +86,7 @@ class Host:
 
 
 def create_variant_generic(
-    task_names: list[str],
+    tasks: list[str | EvgTaskRef],
     display_name: str,
     *,
     host: Host | None = None,
@@ -94,7 +95,12 @@ def create_variant_generic(
     **kwargs: Any,
 ) -> BuildVariant:
     """Create a build variant for the given inputs."""
-    task_refs = [EvgTaskRef(name=n) for n in task_names]
+    task_refs = []
+    for t in tasks:
+        if isinstance(t, EvgTaskRef):
+            task_refs.append(t)
+        else:
+            task_refs.append(EvgTaskRef(name=t))
     expansions = expansions and expansions.copy() or dict()
     if "run_on" in kwargs:
         run_on = kwargs.pop("run_on")
@@ -118,7 +124,7 @@ def create_variant_generic(
 
 
 def create_variant(
-    task_names: list[str],
+    tasks: list[str | EvgTaskRef],
     display_name: str,
     *,
     version: str | None = None,
@@ -133,7 +139,7 @@ def create_variant(
     if python:
         expansions["PYTHON_BINARY"] = get_python_binary(python, host)
     return create_variant_generic(
-        task_names, display_name, version=version, host=host, expansions=expansions, **kwargs
+        tasks, display_name, version=version, host=host, expansions=expansions, **kwargs
     )
 
 
@@ -716,6 +722,27 @@ def create_atlas_connect_variants():
     ]
 
 
+def create_coverage_report_variants():
+    return [create_variant(["coverage-report"], "Coverage Report", host=DEFAULT_HOST)]
+
+
+def create_kms_variants():
+    tasks = []
+    tasks.append(EvgTaskRef(name="test-gcpkms", batchtime=BATCHTIME_WEEK))
+    tasks.append("test-gcpkms-fail")
+    tasks.append(EvgTaskRef(name="test-azurekms", batchtime=BATCHTIME_WEEK))
+    tasks.append("test-azurekms-fail")
+    return [create_variant(tasks, "KMS", host=HOSTS["debian11"])]
+
+
+def create_import_time_variants():
+    return [create_variant(["check-import-time"], "Import Time", host=DEFAULT_HOST)]
+
+
+def create_backport_pr_variants():
+    return [create_variant(["backport-pr"], "Backport PR", host=DEFAULT_HOST)]
+
+
 def create_perf_variants():
     host = HOSTS["perf"]
     return [