ppc64le builds fail when resolving go deps (name mapping?)

### What version of rules_go are you using?
0.39.0
### What version of Bazel are you using?
6.1.1

### Does this issue reproduce with the latest releases of all the above?
yes

### What operating system and processor architecture are you using?
linux, amd64

### Any other potentially useful information about your toolchain?
no

### What did you do?

built a simple go binary using arch ppc64le

WORKSPACE.bazel
```
load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")

http_archive(
name = "io_bazel_rules_go",
sha256 = "6b65cb7917b4d1709f9410ffe00ecf3e160edf674b78c54a894471320862184f",
urls = [
"https://mirror.bazel.build/github.com/bazelbuild/rules_go/releases/download/v0.39.0/rules_go-v0.39.0.zip",
"https://github.com/bazelbuild/rules_go/releases/download/v0.39.0/rules_go-v0.39.0.zip",
],
)

load("@io_bazel_rules_go//go:deps.bzl", "go_register_toolchains", "go_rules_dependencies")

go_rules_dependencies()

go_register_toolchains(version = "1.20.2")
```

BUILD
```
load("@io_bazel_rules_go//go:def.bzl", "go_binary")

go_binary(
name = "hello",
srcs = ["hello.go"],
goarch = "ppc64le",
goos = "linux",
pure = "on",
)
```

hello.go
```
package main

import (
"fmt"
)

func main() {
fmt.Print("hi")
}
```

### What did you expect to see?
It builds like any other architecture (this works with `amd64`, `arm64`, `arm`, `s390x`), but not `ppc64le`

### What did you see instead?
```
hello.go:4:2: could not import fmt (open bazel-out/k8-fastbuild-ST-28dcfbc35f29/bin/external/io_bazel_rules_go/stdlib_/pkg/linux_ppc64le/fmt.a: no such file or directory)
```

It does not build, go dependencies are downloaded somewhere unexpected (`pkg/linux_ppc64`) instead of (`pkg/linux_ppc64le`).

One fix is to remove this line: https://github.com/bazelbuild/rules_go/blob/3125d8f0971bee56f069bbb33beb6686109fb71d/go/private/platforms.bzl#L34 but I assume that has some sort of side effect. I don't know enough bazel or go to debug any further yet.

Reproduce the failure with rules_go 0.39.0, Bazel 6.1.1, and the WORKSPACE, BUILD, and hello.go examples in the report. Start at go/private/platforms.bzl line 34 and compare the ppc64le platform mapping with the generated pkg/linux_ppc64 and pkg/linux_ppc64le paths; done means the hello target resolves fmt and builds for ppc64le without breaking the other listed architectures.

Written by the indexing model from the issue text.