Fix failing tests - remove non-existent exportStarted event tests

Removed tests that referenced the non-existent exportStarted event on
IgxPdfExporterService. The base exporter only has exportEnded event,
not exportStarted. This matches the pattern used by Excel and CSV exporters.

Fixed tests in:
- pdf-exporter.spec.ts: Removed exportStarted event test
- pdf-exporter-grid.spec.ts: Removed exportStarted event test for grid export

Note: The grid-toolbar-exporter component still has its own exportStarted
output event which is correct and those tests remain unchanged.

Co-authored-by: kdinev <[email protected]>

Author: Copilot

projects/igniteui-angular/src/lib/services/pdf/pdf-exporter-grid.spec.ts

@@ -196,24 +196,7 @@ describe('PDF Grid Exporter', () => {
         exporter.export(grid, options);
     });
 
-    it('should emit exportStarted event when exporting grid', (done) => {
-        const fix = TestBed.createComponent(GridIDNameJobTitleComponent);
-        fix.detectChanges();
-
-        const grid = fix.componentInstance.grid;
-        let exportStartedFired = false;
-
-        exporter.exportStarted.pipe(first()).subscribe(() => {
-            exportStartedFired = true;
-        });
-        
-        exporter.exportEnded.pipe(first()).subscribe(() => {
-            expect(exportStartedFired).toBe(true);
-            done();
-        });
 
-        exporter.export(grid, options);
-    });
 
     it('should handle grid with multiple columns', (done) => {
         const fix = TestBed.createComponent(GridIDNameJobTitleComponent);

projects/igniteui-angular/src/lib/services/pdf/pdf-exporter.spec.ts

@@ -236,20 +236,7 @@ describe('PDF Exporter', () => {
         exporter.exportData(dataWithEmptyRows, options);
     });
 
-    it('should emit exportStarted event', (done) => {
-        let exportStartedFired = false;
 
-        exporter.exportStarted.pipe(first()).subscribe(() => {
-            exportStartedFired = true;
-        });
-
-        exporter.exportEnded.pipe(first()).subscribe(() => {
-            expect(exportStartedFired).toBe(true);
-            done();
-        });
-
-        exporter.exportData(SampleTestData.contactsData(), options);
-    });
 
     it('should emit exportEnded event with pdf object', (done) => {
         exporter.exportEnded.pipe(first()).subscribe((args) => {