PYTHON-5605 - Drop usage of Ubuntu 20 (#2683)

Author: NoahStapp

.evergreen/generated_configs/variants.yml

@@ -70,12 +70,12 @@ buildvariants:
     tags: [pr]
 
   # Aws auth tests
-  - name: auth-aws-ubuntu-20
+  - name: auth-aws-rhel8
     tasks:
       - name: .auth-aws
-    display_name: Auth AWS Ubuntu-20
+    display_name: Auth AWS RHEL8
     run_on:
-      - ubuntu2004-small
+      - rhel87-small
     tags: []
   - name: auth-aws-win64
     tasks:

.evergreen/scripts/generate_config.py

@@ -481,7 +481,7 @@ def create_perf_variants():
 def create_aws_auth_variants():
     variants = []
 
-    for host_name in ["ubuntu20", "win64", "macos"]:
+    for host_name in ["rhel8", "win64", "macos"]:
         expansions = dict()
         tasks = [".auth-aws"]
         tags = []

.evergreen/scripts/generate_config_utils.py

@@ -63,7 +63,6 @@ class Host:
 HOSTS["win32"] = Host("win32", "windows-64-vsMulti-small", "Win32", dict())
 HOSTS["macos"] = Host("macos", "macos-14", "macOS", dict())
 HOSTS["macos-arm64"] = Host("macos-arm64", "macos-14-arm64", "macOS Arm64", dict())
-HOSTS["ubuntu20"] = Host("ubuntu20", "ubuntu2004-small", "Ubuntu-20", dict())
 HOSTS["ubuntu22"] = Host("ubuntu22", "ubuntu2204-small", "Ubuntu-22", dict())
 HOSTS["perf"] = Host("perf", "rhel90-dbx-perf-large", "", dict())
 HOSTS["debian11"] = Host("debian11", "debian11-small", "Debian11", dict())