Fix git-latest ansible-lint errors

Reference: https://ansible-lint.readthedocs.io/en/latest/default_rules/#git-latest

Our variable naming is not necessarily consistent across roles.
I've tried to follow the naming conventions of each individual role.
All new variables are suffixed with `_version`, but the prefix may be
somewhat different.

roles/matrix-bridge-mautrix-telegram/defaults/main.yml

@@ -7,11 +7,13 @@ matrix_mautrix_telegram_enabled: true
 matrix_telegram_lottieconverter_container_image_self_build: false
 matrix_telegram_lottieconverter_container_image_self_build_mask_arch: false
 matrix_telegram_lottieconverter_docker_repo: "https://mau.dev/tulir/lottieconverter.git"
+matrix_telegram_lottieconverter_docker_repo_version: "master"
 matrix_telegram_lottieconverter_docker_src_files_path: "{{ matrix_base_data_path }}/lotticonverter/docker-src"
 matrix_telegram_lottieconverter_docker_image: "dock.mau.dev/tulir/lottieconverter:alpine-3.15"  # needs to be ajusted according to FROM clause of Dockerfile of mautrix-telegram
 
 matrix_mautrix_telegram_container_image_self_build: false
 matrix_mautrix_telegram_docker_repo: "https://mau.dev/mautrix/telegram.git"
+matrix_mautrix_telegram_docker_repo_version: "{{ 'master' if matrix_mautrix_telegram_version == 'latest' else matrix_mautrix_telegram_version }}"
 matrix_mautrix_telegram_docker_src_files_path: "{{ matrix_base_data_path }}/mautrix-telegram/docker-src"
 
 matrix_mautrix_telegram_version: v0.11.3

roles/matrix-bridge-mautrix-telegram/tasks/setup_install.yml

@@ -63,6 +63,7 @@
 - name: Ensure lottieconverter is present when self-building
   ansible.builtin.git:
     repo: "{{ matrix_telegram_lottieconverter_docker_repo }}"
+    version: "{{ matrix_telegram_lottieconverter_docker_repo_version }}"
     dest: "{{ matrix_telegram_lottieconverter_docker_src_files_path }}"
     force: "yes"
   become: true
@@ -85,6 +86,7 @@
 - name: Ensure matrix-mautrix-telegram repository is present when self-building
   ansible.builtin.git:
     repo: "{{ matrix_mautrix_telegram_docker_repo }}"
+    version: "{{ matrix_mautrix_telegram_docker_repo_version }}"
     dest: "{{ matrix_mautrix_telegram_docker_src_files_path }}"
     force: "yes"
   become: true