fix: resolve Dependabot configuration issues

Remove non-existent security-team references from reviewers and assignees.
The required labels (security, github-actions, python, docker) have been
created directly in the repository.

This fixes the configuration errors reported in PRs #22 and #23.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: garland3

.github/dependabot.yml

@@ -9,10 +9,6 @@ updates:
       day: "monday"
       time: "09:00"
     open-pull-requests-limit: 10
-    reviewers:
-      - "security-team"
-    assignees:
-      - "security-team"
     commit-message:
       prefix: "security(deps)"
       include: "scope"
@@ -37,10 +33,6 @@ updates:
       day: "monday"
       time: "09:00"
     open-pull-requests-limit: 10
-    reviewers:
-      - "security-team"
-    assignees:
-      - "security-team"
     commit-message:
       prefix: "security(deps)"
       include: "scope"
@@ -69,10 +61,6 @@ updates:
       interval: "weekly"
       day: "tuesday"
       time: "09:00"
-    reviewers:
-      - "security-team"
-    assignees:
-      - "security-team"
     commit-message:
       prefix: "security(docker)"
     labels:
@@ -87,10 +75,6 @@ updates:
       interval: "weekly"
       day: "wednesday"
       time: "09:00"
-    reviewers:
-      - "security-team"
-    assignees:
-      - "security-team"
     commit-message:
       prefix: "security(actions)"
     labels: