Pin rust version to stop filling up my poor unraid server

.gitlab-ci.yml

@@ -1,3 +1,5 @@
+image: rust:1.75
+
 stages:
   - build
   - lint
@@ -12,13 +14,11 @@ variables:
   SCHEDULED_PIPELINE_NAME: "Daily scheduled build pipeline"
 
 build:
-  image: rust:latest
   stage: build
   script:
     - cargo build
 
 lint:
-  image: rust:latest
   stage: lint
   script:
     - rustup component add clippy
@@ -27,7 +27,6 @@ lint:
     - if: "$CI_COMMIT_BRANCH != $CI_DEFAULT_BRANCH"
 
 test:
-  image: rust:latest
   stage: test
   script:
     - cargo test --verbose
@@ -35,7 +34,6 @@ test:
     - if: "$CI_COMMIT_BRANCH != $CI_DEFAULT_BRANCH"
 
 build_site:
-  image: rust:latest
   stage: build_site
   script:
     - cargo run