Bump nav_version from 2.8.3 to 2.8.4 in /14_pushes

Bumps `nav_version` from 2.8.3 to 2.8.4.

Updates `androidx.navigation:navigation-fragment-ktx` from 2.8.3 to 2.8.4

Updates `androidx.navigation:navigation-ui-ktx` from 2.8.3 to 2.8.4

---
updated-dependencies:
- dependency-name: androidx.navigation:navigation-fragment-ktx
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: androidx.navigation:navigation-ui-ktx
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

14_pushes/app/build.gradle

@@ -50,7 +50,7 @@ dependencies {
     def activity_version = "1.9.3"
     def lifecycle_version = "2.8.7"
     def gson_version = "2.11.0"
-    def nav_version = "2.8.3"
+    def nav_version = "2.8.4"
     def room_version = "2.6.1"
     def firebase_version = "33.5.1"
     def play_services_base_version = "18.5.0"