Using %workspace% variable in source.json for a module registry

### Description of the bug:

We have created our own registry index to fetch external dependencies.
In source.json file for a specific module we are able to use environment variable "%workspace%" in windows environment but does not work on Linux (redhat-7)

### Which category does this issue belong to?

External Dependency

### What's the simplest, easiest way to reproduce this bug? Please provide a minimal example if possible.

Below url works in windows environment but not in linux.
{
"url": "file:///%workspace%/thirdparty/abc.tar.gz"
}

Error :
java.lang.IllegalArgumentException: Malformed escape pair: /%workspace%/thirdparty/abc.tar.gz

### Which operating system are you running Bazel on?

Redhat-7 and Windows 10

### What is the output of `bazel info release`?

release 7.0.0

### If `bazel info release` returns `development version` or `(@non-git)`, tell us how you built Bazel.

_No response_

### What's the output of `git remote get-url origin; git rev-parse master; git rev-parse HEAD` ?

_No response_

### Is this a regression? If yes, please try to identify the Bazel commit where the bug was introduced.

_No response_

### Have you found anything relevant by searching the web?

_No response_

### Any other information, logs, or outputs that you want to share?

"local_path" in source.json also does not seem to work.
e.g
type:local_path
path: ../thirdparty/abc.tar.gz

Start by reproducing the minimal source.json example with file:///%workspace%/thirdparty/abc.tar.gz on Red Hat 7 and Windows 10 using Bazel 7.0.0. Then investigate how source.json handles the %workspace% variable and the local_path example path: ../thirdparty/abc.tar.gz. Done means both forms behave consistently on Linux and Windows, with coverage for the reported cases.

Written by the indexing model from the issue text.