Disable RLS for one page in the report by adding duplicated dimension

No, you can't disable RLS from within a measure. What you could do is build a summary table of your data at the granularity you need and then link all dimensions except shop and then link a duplicate of the shop dimension without RLS, as you suggested.

For example, if you only need to show data at the month granularity you could create a summary table like

Sales Summary =
ADDCOLUMNS (
    SUMMARIZE (
        Sales,
        'Product'[Product Key],
        'Shop'[Shop Key],
        'Date'[Year Month]
    ),
    "Sales Value", [Sales Amount]
)

You would then link Date, Product and new duplicate of Shop to this summary table and write the measures you need.

You could go down to any granularity in the summary, but the more columns you add the bigger the table will get.