I was originally going to submit this as an issue on GitHub, but there was a note there about using this forum, so if this isn't the preferred place to submit this, sorry about that!
jQuery Migrate 3.4.0 flags line 295 in dataTables.buttons.js (viewable on GitHub here) because removeAttr() no longer sets boolean properties. I'm using jQuery Migrate 3.4.0, jQuery 3.6.1, DataTables 1.12.1, and DataTables Buttons 2.2.3
Here is the full jQuery Migrate error:
JQMIGRATE: jQuery.fn.removeAttr no longer sets boolean properties: disabled
migrateWarn @ jquery-migrate-3.4.0.js:135
(anonymous) @ jquery-migrate-3.4.0.js:426
each @ jquery_3.6.1.min.js:2
(anonymous) @ jquery-migrate-3.4.0.js:424
obj.<computed> @ jquery-migrate-3.4.0.js:180
enable @ datatables.min.js:238
(anonymous) @ datatables.min.js:273
each @ datatables.min.js:148
(anonymous) @ datatables.min.js:273
(anonymous) @ datatables.min.js:152
(anonymous) @ datatables.min.js:414
dispatch @ jquery_3.6.1.min.js:2
y.handle @ jquery_3.6.1.min.js:2
trigger @ jquery_3.6.1.min.js:2
(anonymous) @ jquery_3.6.1.min.js:2
each @ jquery_3.6.1.min.js:2
each @ jquery_3.6.1.min.js:2
trigger @ jquery_3.6.1.min.js:2
u @ datatables.min.js:393
(anonymous) @ datatables.min.js:407
iterator @ datatables.min.js:149
(anonymous) @ datatables.min.js:407
(anonymous) @ datatables.min.js:154
(anonymous) @ datatables.min.js:152
E @ datatables.min.js:399
(anonymous) @ datatables.min.js:392
dispatch @ jquery_3.6.1.min.js:2
y.handle @ jquery_3.6.1.min.js:2