Share-based compensation - Share-based award activity (Details) - shares	Dec. 29, 2023	Jun. 30, 2023	Dec. 30, 2022	Jun. 24, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of ordinary shares available for future grant (in shares)	1,870,190
2020 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of ordinary shares available for future grant (in shares)	1,758,843
2017 Inducement Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of ordinary shares available for future grant (in shares)	111,347
Restricted share units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share units outstanding (in shares)	327,764	368,765	404,053	459,626
Restricted share units | 2020 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share units outstanding (in shares)	327,764
Restricted share units | 2017 Inducement Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share units outstanding (in shares)	0
Performance share units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share units outstanding (in shares)	171,078	204,016	204,016	285,882
Performance share units | 2020 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share units outstanding (in shares)	171,078
Performance share units | 2017 Inducement Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share units outstanding (in shares)	0