builtin/credential-cache: fix missing parameter for stub function

builtin/credential-cache: fix missing parameter for stub function

When not compiling the credential cache we may use a stub function for
`cmd_credential_cache()`. With commit 9b1cb5070f (builtin: add a
repository parameter for builtin functions, 2024-09-13), we have added a
new parameter to all of those top-level `cmd_*()` functions, and did
indeed adapt the non-stubbed-out `cmd_credential_cache()`. But we didn't
adapt the stubbed-out variant, so the code does not compile.

Fix this by adding the missing parameter.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Taylor Blau <me@ttaylorr.com>