Libraries exported by cc_shared_library can be dropped by the linker

### Description of the bug:

If a library (without `alwayslink = True`) is exported by a cc_shared_library but unused, the linker drops the library. This is problematic since if a shared library (`A`) depends on a shared library (`B`), it expects any of its dependencies that are exported by `B` to be fulfilled by `B`, and therefore does not link them into `A`. The only way of avoiding this is to specify this dropped library in `deps`.

I would expect libraries that match the exports filter to be treated as if they were alwayslink, i.e. not put them inside `-Wl,--start-lib` and `-Wl,--end-lib`.

There is a slack thread about this here: https://bazelbuild.slack.com/archives/CGA9QFQ8H/p1701702759075819

### Which category does this issue belong to?

_No response_

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

I have created a reproducer of this issue here: https://github.com/cameron-martin/bazel-7-cc-shared-library-dropping-exported

Running `bazel build //:bin` reproduces this error, getting a linker error due to the dropped library.

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

Ubuntu 20.04

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

release 7.0.0rc5

### 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?

_No response_

Start with the linked reproducer and run `bazel build //:bin` to observe the linker failure. Trace how `cc_shared_library` applies its exports filter and handles unused libraries, then verify that an exported library is retained without adding it to `deps`.

Written by the indexing model from the issue text.