chore: make startActiveSpan required in the tracer interface

Signed-off-by: naseemkullah <naseem@transit.app>

Author: naseemkullah

src/trace/ProxyTracer.ts

@@ -38,15 +38,9 @@ export class ProxyTracer implements Tracer {
     return this._getTracer().startSpan(name, options, context);
   }
 
-  startActiveSpan?<F extends (span: Span) => ReturnType<F>>():
-    | ReturnType<F>
-    | undefined {
+  startActiveSpan<F extends (span: Span) => ReturnType<F>>(): ReturnType<F> {
     const tracer = this._getTracer();
-
-    if (tracer.startActiveSpan) {
-      return Reflect.apply(tracer.startActiveSpan, tracer, arguments);
-    }
-    return;
+    return Reflect.apply(tracer.startActiveSpan, tracer, arguments);
   }
 
   /**

src/trace/tracer.ts

@@ -78,16 +78,16 @@ export interface Tracer {
    *   do some more work
    *   span.end();
    */
-  startActiveSpan?<F extends (span: Span) => ReturnType<F>>(
+  startActiveSpan<F extends (span: Span) => ReturnType<F>>(
     name: string,
     fn: F
   ): ReturnType<F>;
-  startActiveSpan?<F extends (span: Span) => ReturnType<F>>(
+  startActiveSpan<F extends (span: Span) => ReturnType<F>>(
     name: string,
     options: SpanOptions,
     fn: F
   ): ReturnType<F>;
-  startActiveSpan?<F extends (span: Span) => ReturnType<F>>(
+  startActiveSpan<F extends (span: Span) => ReturnType<F>>(
     name: string,
     options: SpanOptions,
     context: Context,