chore: update labels of issue templates

Author: lars-reimann

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -1,6 +1,6 @@
 name: 'Bug report'
 description: 'Report that something does not work as expected'
-labels: ['bug']
+labels: ['bug :beetle:']
 
 body:
   - type: textarea

.github/ISSUE_TEMPLATE/feature_request.yml

@@ -1,6 +1,6 @@
 name: 'Feature request'
 description: 'Suggest an idea for this project'
-labels: ['enhancement']
+labels: ['enhancement :bulb:']
 
 body:
   - type: textarea

.github/ISSUE_TEMPLATE/missing_annotation.yml

@@ -1,6 +1,6 @@
 name: 'Missing annotation (autogen)'
 description: "An annotation should have been generated automatically but wasn't."
-labels: ['bug', 'missing annotation']
+labels: ['bug :beetle:', 'missing annotation']
 
 body:
   - type: input

.github/ISSUE_TEMPLATE/wrong_annotation.yml

@@ -1,6 +1,6 @@
 name: 'Wrong annotation (autogen)'
 description: 'An annotation was generated automatically but is incorrect.'
-labels: ['bug', 'wrong annotation']
+labels: ['bug :beetle:', 'wrong annotation']
 
 body:
   - type: input