Update CI pipeline to use more recent versions

* Use python:3.11 image and gcc:11 and gcc:12 image in CI pipeline.
* GoogleTest v1.13.0 supports only C++ >= 14. This requirement is not
  met with gcc:10, hence remove CI jobs with gcc:10 image.

.gitlab-ci.yml

@@ -12,7 +12,7 @@ stages:
   - run
 
 license_compliance:
-  image: python:3.10
+  image: python:3.11
   stage: lint
   before_script:
     - pip install --upgrade pip
@@ -21,7 +21,7 @@ license_compliance:
     - reuse lint
 
 lint:
-  image: python:3.10
+  image: python:3.11
   stage: lint
   before_script:
     - pip install --upgrade pip
@@ -29,19 +29,6 @@ lint:
   script:
     - cpplint --recursive src/ tests/
 
-build:gcc:10:
-  image: gcc:10
-  stage: build
-  before_script:
-    - apt-get update && apt-get -qy install python3 python3-pip
-    - pip3 install cmake
-  script:
-    - cmake -S . -B build
-    - cmake --build build
-  artifacts:
-    paths:
-      - build/
-
 build:gcc:11:
   image: gcc:11
   stage: build
@@ -68,17 +55,6 @@ build:gcc:12:
     paths:
       - build/
 
-test:gcc:10:
-  image: gcc:10
-  stage: test
-  before_script:
-    - apt-get update && apt-get -qy install python3 python3-pip
-    - pip3 install cmake
-  script:
-    - cd build && ctest
-  dependencies:
-    - build:gcc:10
-
 test:gcc:11:
   image: gcc:11
   stage: test
@@ -102,11 +78,11 @@ test:gcc:12:
     - build:gcc:12
 
 run:
-  image: gcc:11
+  image: gcc:12
   stage: run
   script:
     - ./build/bin/helloWorld
   dependencies:
-    - build:gcc:11
+    - build:gcc:12
 
 ...