fix(sliding-sync): ensure last index is also invalidated

Index ranges are inclusive, but our loop would stop one short. This particuarly
tricky when the selective view is moved, as we didn't properly invalidate all items.

crates/matrix-sdk/src/sliding_sync.rs

@@ -1419,7 +1419,9 @@ impl SlidingSyncView {
                         ));
                     }
 
-                    while pos < end {
+                    // ranges are inclusive up to the last index. e.g. `[0, 10]`; `[0, 0]`.
+                    // ensure we pick them all up
+                    while pos <= end {
                         if pos as usize >= max_len {
                             break; // how does this happen?
                         }