[Integration][Format] Inconsistent skips in datagen

### Describe the bug, including details regarding any error messages, version, and platform.

I'm looking at the current [`datagen.py`](https://github.com/apache/arrow/blob/main/dev/archery/archery/integration/datagen.py) and I see some type-specific skips that seem inconsistent with the current [implementation status](https://arrow.apache.org/docs/dev/status.html).

Specifically:

* https://github.com/apache/arrow/blob/4eca50770f7f2c5938a676f0719fbfc8aae4803c/dev/archery/archery/integration/datagen.py#L1933-L1935
(decimal256 is supported in JS?)

* https://github.com/apache/arrow/blob/4eca50770f7f2c5938a676f0719fbfc8aae4803c/dev/archery/archery/integration/datagen.py#L1936-L1950
(decimal32/64 are supported in Go, Rust and nanoarrovw?)

* https://github.com/apache/arrow/blob/4eca50770f7f2c5938a676f0719fbfc8aae4803c/dev/archery/archery/integration/datagen.py#L2001-L2007
(REE is supported in nanoarrow?)

* https://github.com/apache/arrow-nanoarrow/issues/622
(binary view is supported in Rust and nanoarrow?)

* https://github.com/apache/arrow/blob/4eca50770f7f2c5938a676f0719fbfc8aae4803c/dev/archery/archery/integration/datagen.py#L2016-L2022
(list view in supported in Rust and nanoarrow?)

* https://github.com/apache/arrow/blob/4eca50770f7f2c5938a676f0719fbfc8aae4803c/dev/archery/archery/integration/datagen.py#L2024-L2028
(extension is supported in nanoarrow?)

### Component(s)

Format, Integration