Limit documentation to basic glob patterns

Author: herin049

instrumentation/opentelemetry-instrumentation-system-metrics/src/opentelemetry/instrumentation/system_metrics/__init__.py

@@ -164,7 +164,7 @@ def _build_default_config() -> dict[str, list[str] | None]:
         for pat in os.environ.get(
             OTEL_PYTHON_SYSTEM_METRICS_EXCLUDED_METRICS, ""
         ).split(",")
-        if pat
+        if pat.strip()
     ]
     if excluded_metrics:
         return {

instrumentation/opentelemetry-instrumentation-system-metrics/src/opentelemetry/instrumentation/system_metrics/environment_variables.py

@@ -41,9 +41,6 @@
 The environment variable supports standard glob patterns for metric filtering:
 
 - ``*`` - Matches any sequence of characters within a metric name
-- ``?`` - Matches any single character
-- ``[seq]`` - Matches any character in the sequence
-- ``[!seq]`` - Matches any character not in the sequence
 
 **Example Patterns:**