fix gitlab yml syntax

.gitlab-ci.yml

 image: git.fossgalaxy.com:8042/oci/podman:latest
 
-python:3.10
+python:3.10:
   variables:
     IMAGE_NAME: python
-    IMAGE_TAG: 3.10
-    SOURCE_TAG: 3.10-slim
+    IMAGE_TAG: "3.10"
+    SOURCE_TAG: "3.10-slim"
   script:
     - ./build.sh
 
-python:3.10:alpine
+python:3.10:alpine:
   variables:
     IMAGE_NAME: python
-    IMAGE_TAG: 3.10-alpine
-    SOURCE_TAG: 3.10-alpine
+    IMAGE_TAG: "3.10-alpine"
+    SOURCE_TAG: "3.10-alpine"
   script:
     - ./build.sh
 
-python:3.12
+python:3.12:
   variables:
     IMAGE_NAME: python
-    IMAGE_TAG: 3.12
-    SOURCE_TAG: 3.12-slim
+    IMAGE_TAG: "3.12"
+    SOURCE_TAG: "3.12-slim"
   script:
     - ./build.sh
 
-python:3.12:alpine
+python:3.12:alpine:
   variables:
     IMAGE_NAME: python
-    IMAGE_TAG: 3.12-alpine
-    SOURCE_TAG: 3.12-alpine
+    IMAGE_TAG: "3.12-alpine"
+    SOURCE_TAG: "3.12-alpine"
   script:
     - ./build.sh