build(deps): update core dependency to version 1.2.0

- Update core dependency ref from specific commit hash to version tag v1.2.0
- Update resolved ref to new commit hash corresponding to v1.2.0 tag
- Update version in pubspec.lock from 0.0.0 to 1.2.0

Author: fulleni

pubspec.lock

@@ -69,11 +69,11 @@ packages:
     dependency: "direct main"
     description:
       path: "."
-      ref: "828b984517edec069266579c624c7af9fbe0e2ac"
-      resolved-ref: "828b984517edec069266579c624c7af9fbe0e2ac"
+      ref: "v1.2.0"
+      resolved-ref: d052799c1ebb7bcdd1a725a2a7919948c14fa001
       url: "https://github.com/flutter-news-app-full-source-code/core.git"
     source: git
-    version: "0.0.0"
+    version: "1.2.0"
   coverage:
     dependency: transitive
     description:

pubspec.yaml

@@ -10,7 +10,7 @@ dependencies:
   core:
     git:
       url: https://github.com/flutter-news-app-full-source-code/core.git
-      ref: 828b984517edec069266579c624c7af9fbe0e2ac
+      ref: v1.2.0
 
 dev_dependencies:
   mocktail: ^1.0.4