chore(deps): bump github.com/spf13/viper from 1.16.0 to 1.18.2 (#4861)

* chore(deps): bump github.com/spf13/viper from 1.16.0 to 1.18.2

Bumps [github.com/spf13/viper](https://github.com/spf13/viper) from 1.16.0 to 1.18.2.
- [Release notes](https://github.com/spf13/viper/releases)
- [Commits](https://github.com/spf13/viper/compare/v1.16.0...v1.18.2)

---
updated-dependencies:
- dependency-name: github.com/spf13/viper
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

* fix race

---------

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Caleb Doxsey <cdoxsey@pomerium.com>

internal/log/multiwriter.go

@@ -0,0 +1,48 @@
+package log
+
+import (
+	"io"
+	"slices"
+	"sync"
+)
+
+// A MultiWriter dispatches writes to multiple writers.
+type MultiWriter struct {
+	mu sync.Mutex
+	ws []io.Writer
+}
+
+// NewMultiWriter creates a new MultiWriter
+func NewMultiWriter() *MultiWriter {
+	return &MultiWriter{}
+}
+
+// Add adds a writer to the multi writer.
+func (m *MultiWriter) Add(w io.Writer) {
+	m.mu.Lock()
+	m.ws = append(m.ws, w)
+	m.mu.Unlock()
+}
+
+// Remove removes a writer from the multi writer.
+func (m *MultiWriter) Remove(w io.Writer) {
+	m.mu.Lock()
+	m.ws = slices.DeleteFunc(m.ws, func(mw io.Writer) bool {
+		return mw == w
+	})
+	m.mu.Unlock()
+}
+
+// Write writes data to all the writers. The last count and error are returned.
+func (m *MultiWriter) Write(data []byte) (int, error) {
+	var n int
+	var err error
+
+	m.mu.Lock()
+	for _, w := range m.ws {
+		n, err = w.Write(data)
+	}
+	m.mu.Unlock()
+
+	return n, err
+}