fix: repos.last_synced_at

Signed-off-by: Mouad BANI <mouad-mb@outlook.com>

Author: mbani01

backend/src/osspckgs/migrations/V1779799200__repos_default_created_and_last_synced.sql

@@ -0,0 +1,6 @@
+ALTER TABLE repos
+    ALTER COLUMN created_at SET DEFAULT NOW();
+
+ALTER TABLE repos
+    ALTER COLUMN last_synced_at DROP NOT NULL,
+    ALTER COLUMN last_synced_at DROP DEFAULT;