longitudinal reports: save as webp

tools/longitudinal_maneuvers/generate_report.py

@@ -120,9 +120,9 @@ def report(platform, route, _description, CP, ID, maneuvers):
       fig.tight_layout()
 
       buffer = io.BytesIO()
-      fig.savefig(buffer, format='png')
+      fig.savefig(buffer, format='webp')
       buffer.seek(0)
-      builder.append(f"<img src='data:image/png;base64,{base64.b64encode(buffer.getvalue()).decode()}' style='width:100%; max-width:800px;'>\n")
+      builder.append(f"<img src='data:image/webp;base64,{base64.b64encode(buffer.getvalue()).decode()}' style='width:100%; max-width:800px;'>\n")
       builder.append("</details>\n")
 
   summary = ["<h2>Summary</h2>\n"]