reftable in jgit doesn't respect changes outside of jgit

[zotttelbart]

Version

7.0.0

Operating System

Windows

Bug description

Changes on reftable outside of jgit (example gitbash) are not visible for jgit

Actual behavior

` Git git = Git.init().setDirectory(new File("c:\temp\jgit")).call();

	git.remoteAdd().setUri(new URIish("https://github.com/eclipse-jgit/jgit.git")).setName("origin").call();
	git.fetch().setRemote("origin").setProgressMonitor(new TextProgressMonitor()).call();
	git.checkout().setName("master").setStartPoint("origin/master").setCreateBranch(true).call();
	((FileRepository) git.getRepository()).convertRefStorage("reftable", true, false);
	

	git.tag().setName("foo").call();
	System.out.println(git.getRepository().findRef("foo"));

	System.out.println("Now change the Tag via git bash (git tag --force foo v7.0.0.202408201547-m3)");
	System.out.println("and press enter. You will see, the tag in jgit doesn't change");
	Scanner scanner = new Scanner(System.in);
	scanner.next();
	
	System.out.println(git.getRepository().exactRef("refs/tags/foo"));
	
	git.close();

`

outputs:

`Ref[refs/tags/foo=ef0923a81c00465034705a24a30b4c8d6878729f(3)]
Now change the Tag via git bash (git tag --force foo v7.0.0.202408201547-m3)
and press enter. You will see, the tag in jgit doesn't change

Ref[refs/tags/foo=ef0923a81c00465034705a24a30b4c8d6878729f(3)]
`

For jgit, the ref didn't change

output from gitbash

`$ git tag --force foo v7.0.0.202408201547-m3
Unlink of file 'C:/temp/jgit/.git/reftable/000000000003-000000000003-1b2b152a.ref' failed. Should I try again? (y/n) y
Unlink of file 'C:/temp/jgit/.git/reftable/000000000003-000000000003-1b2b152a.ref' failed. Should I try again? (y/n) y
Unlink of file 'C:/temp/jgit/.git/reftable/000000000003-000000000003-1b2b152a.ref' failed. Should I try again? (y/n) n
Unlink of file 'C:/temp/jgit/.git/reftable/000000000003-000000000003-1b2b152a.ref' failed. Should I try again? (y/n) n
Updated tag 'foo' (was ef0923a81)

$ git show-ref | grep foo
727666694e80ed39488451503d72f65bb4ef69f8 refs/tags/foo
`

you see #101 but the ref is changed

Expected behavior

Changes on tables.list should call

ReftableDatabase.clearCache() and
FileReftableStack.reload()

in FileReftableDatabase

Relevant log output

No response

Other information

I hope, this helps to improve jgit :)