Add optional architecture attribution to receipt attribute annotations

**What are you trying to do?**
I would like to distinguish between macos on an arm architecture (M1 silicone) versus macos on an x86 via the receipt attributes

**What's your proposed solution?**
Something like this:

```text
[macos]
foo:
echo "running on a mac and don't care about architecture"

[macos(arch(x86_64))]
bar:
echo "running on a mac with x86_64 architecture"

[macos(arch(aarch64))]]
baz:
echo "running on a mac with M1 architecture
```

**Additional context**
The capability should be able to leverage the existing [system information](https://just.systems/man/en/chapter_31.html?highlight=oper#system-information) functions. If this can be done then any mix of operating system receipt attributes and system information functions could be used.

Start by reading the receipt attribute annotation handling and the linked system information documentation, focusing on how operating-system attributes and system information functions are represented. Done should include optional architecture-qualified macOS attributes, support for the proposed combinations, and preservation of existing unqualified attributes.

Written by the indexing model from the issue text.