chore: remove ignore file caching entirely (#10813)

Effectively nobody uses it, it cost more than it was worth, the code
doesn't carry its weight. Remove it and let any similar mechanism in the
future be an internal implementation detail.

Closes #10812

Signed-off-by: Jakob Borg <jakob@kastelo.net>

lib/model/model_test.go

@@ -1603,7 +1603,7 @@ func TestIgnores(t *testing.T) {
 		ID: "fresh", Path: "XXX",
 		FilesystemType: config.FilesystemTypeFake,
 	}
-	ignores := ignore.New(fcfg.Filesystem(), ignore.WithCache(m.cfg.Options().CacheIgnoredFiles))
+	ignores := ignore.New(fcfg.Filesystem())
 	m.mut.Lock()
 	m.folderCfgs[fcfg.ID] = fcfg
 	m.folderIgnores[fcfg.ID] = ignores
@@ -1618,7 +1618,7 @@ func TestIgnores(t *testing.T) {
 	pausedDefaultFolderConfig := defaultFolderConfig
 	pausedDefaultFolderConfig.Paused = true
 
-	m.restartFolder(defaultFolderConfig, pausedDefaultFolderConfig, false)
+	m.restartFolder(defaultFolderConfig, pausedDefaultFolderConfig)
 	// Here folder initialization is not an issue as a paused folder isn't
 	// added to the model and thus there is no initial scan happening.
 
@@ -2216,7 +2216,7 @@ func TestIndexesForUnknownDevicesDropped(t *testing.T) {
 		t.Error("expected two devices")
 	}
 
-	m.newFolder(defaultFolderConfig, false)
+	m.newFolder(defaultFolderConfig)
 	defer cleanupModel(m)
 
 	if devs, err := m.sdb.ListDevicesForFolder("default"); err != nil || len(devs) != 1 {