…lastic#114407)

**Description:**

This PR addresses the issue described in [elastic#114402](elastic#114402), where the `synthetic_source` feature does not correctly handle the `bit` type in `dense_vector` fields when `index` is set to `false`. The root cause of the issue was that the `bit` type was not properly accounted for, leading to an array that is 8 times the size of the actual `dims` value of docvalue. This mismatch will causes an array out-of-bounds exception when reconstructing the document.

**Changes:**

- Adjusted the `synthetic_source` logic to correctly handle the `bit` type by ensuring the array size accounts for the 8x difference in dimensions.
- Added yaml test to cover the `bit` type scenario in `dense_vector` fields with `index` set to `false`.

**Related Issues:**

- Closes [elastic#114402](elastic#114402)
- Introduced in [elastic#110059](elastic#110059)