Fix #108786: Logic errors with pinned islands inside uv packer

Pinning information was accidentally skipped inside of the
UV packing engine because of their ordering.

This was most noticeable when using the "Bounding Box" shape
method, causing some pinned islands to be moved when they
should have been locked in place.

source/blender/geometry/intern/uv_pack.cc

@@ -1781,7 +1781,7 @@ static float pack_islands_scale_margin(const Span<PackIsland *> islands,
   rctf locked_bounds = {0.0f};     /* AABB of islands which can't translate. */
   int64_t locked_island_count = 0; /* Index of first non-locked island. */
   for (int64_t i = 0; i < islands.size(); i++) {
-    PackIsland *pack_island = islands[i];
+    PackIsland *pack_island = islands[aabbs[i]->index];
     if (pack_island->can_translate_(params)) {
       break;
     }
@@ -1794,6 +1794,12 @@ static float pack_islands_scale_margin(const Span<PackIsland *> islands,
     }
     float2 top_right = pack_island->pivot_ + pack_island->half_diagonal_;
     BLI_rctf_do_minmax_v(&locked_bounds, top_right);
+
+    uv_phi &phi = r_phis[aabbs[i]->index]; /* Lock in place. */
+    phi.translation = pack_island->pivot_;
+    sub_v2_v2(phi.translation, params.udim_base_offset);
+    phi.rotation = 0.0f;
+
     locked_island_count = i + 1;
   }