fix: resolve clippy write_literal warnings under -D warnings

Pass string literals directly to writeln! instead of through an empty
format string. Add .gitignore for build artifacts.

Author: Jaro-c

.gitignore

@@ -13,3 +13,6 @@ fuzz/artifacts/
 
 # Merge conflicts
 *.orig
+
+# Build artifacts
+/target

tests/parse/anchors.rs

@@ -93,7 +93,6 @@ fn include_absolute_path_rejected() {
     let main = dir.path().join("docker-compose.yml");
     writeln!(
         std::fs::File::create(&main).unwrap(),
-        "{}",
         "include:\n  - /etc/passwd\nservices:\n  app:\n    image: alpine"
     )
     .unwrap();
@@ -106,7 +105,6 @@ fn include_parent_traversal_rejected() {
     let main = dir.path().join("docker-compose.yml");
     writeln!(
         std::fs::File::create(&main).unwrap(),
-        "{}",
         "include:\n  - ../../secret.yml\nservices:\n  app:\n    image: alpine"
     )
     .unwrap();
@@ -119,7 +117,6 @@ fn extends_file_absolute_path_rejected() {
     let main = dir.path().join("docker-compose.yml");
     writeln!(
         std::fs::File::create(&main).unwrap(),
-        "{}",
         "services:\n  app:\n    extends:\n      service: base\n      file: /etc/shadow"
     )
     .unwrap();
@@ -132,7 +129,6 @@ fn extends_file_parent_traversal_rejected() {
     let main = dir.path().join("docker-compose.yml");
     writeln!(
         std::fs::File::create(&main).unwrap(),
-        "{}",
         "services:\n  app:\n    extends:\n      service: base\n      file: ../../other.yml"
     )
     .unwrap();

tests/parse/extends.rs

@@ -131,7 +131,6 @@ fn extends_with_external_file() {
     let mut f = std::fs::File::create(&common_path).unwrap();
     writeln!(
         f,
-        "{}",
         r#"
 services:
   base:
@@ -146,7 +145,6 @@ services:
     let mut m = std::fs::File::create(&main_path).unwrap();
     writeln!(
         m,
-        "{}",
         r#"
 services:
   app:

tests/parse/include.rs

@@ -8,7 +8,6 @@ fn include_string_form_merges_services() {
     let included = dir.path().join("services.yml");
     writeln!(
         std::fs::File::create(&included).unwrap(),
-        "{}",
         r#"
 services:
   helper:
@@ -20,7 +19,6 @@ services:
     let main = dir.path().join("docker-compose.yml");
     writeln!(
         std::fs::File::create(&main).unwrap(),
-        "{}",
         r#"
 include:
   - ./services.yml
@@ -44,7 +42,6 @@ fn include_long_form_parses() {
     let inc = dir.path().join("inc.yml");
     writeln!(
         std::fs::File::create(&inc).unwrap(),
-        "{}",
         r#"
 services:
   inc_svc:
@@ -56,7 +53,6 @@ services:
     let main = dir.path().join("docker-compose.yml");
     writeln!(
         std::fs::File::create(&main).unwrap(),
-        "{}",
         r#"
 include:
   - path: ./inc.yml
@@ -80,7 +76,6 @@ fn parent_overrides_included_service() {
     let inc = dir.path().join("inc.yml");
     writeln!(
         std::fs::File::create(&inc).unwrap(),
-        "{}",
         r#"
 services:
   shared:
@@ -92,7 +87,6 @@ services:
     let main = dir.path().join("docker-compose.yml");
     writeln!(
         std::fs::File::create(&main).unwrap(),
-        "{}",
         r#"
 include:
   - ./inc.yml