PYTHON-4783 Remove reference to RHEL7 in tests (#2643)

Author: blink1073

.evergreen/scripts/generate_config_utils.py

@@ -63,7 +63,6 @@ class Host:
 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["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"]