[bugfix] Fix remote media pruning failing if media already gone (#548)

* fix error check of prune to allow missing files

* update go-store library, add test for pruning item with db entry but no file

Signed-off-by: kim <grufwub@gmail.com>

* remove now-unneccessary error check

Signed-off-by: kim <grufwub@gmail.com>

Co-authored-by: kim <grufwub@gmail.com>

vendor/codeberg.org/gruf/go-errors/v2/once.go

@@ -0,0 +1,47 @@
+package errors
+
+import (
+	"sync/atomic"
+	"unsafe"
+)
+
+// OnceError is an error structure that supports safe multi
+// threaded usage and setting only once (until reset).
+type OnceError struct{ err unsafe.Pointer }
+
+// NewOnce returns a new OnceError instance.
+func NewOnce() OnceError {
+	return OnceError{
+		err: nil,
+	}
+}
+
+// Store will safely set the OnceError to value, no-op if nil.
+func (e *OnceError) Store(err error) {
+	// Nothing to do
+	if err == nil {
+		return
+	}
+
+	// Only set if not already
+	atomic.CompareAndSwapPointer(
+		&e.err,
+		nil,
+		unsafe.Pointer(&err),
+	)
+}
+
+// Load will load the currently stored error.
+func (e *OnceError) Load() error {
+	return *(*error)(atomic.LoadPointer(&e.err))
+}
+
+// IsSet returns whether OnceError has been set.
+func (e *OnceError) IsSet() bool {
+	return (atomic.LoadPointer(&e.err) != nil)
+}
+
+// Reset will reset the OnceError value.
+func (e *OnceError) Reset() {
+	atomic.StorePointer(&e.err, nil)
+}