Rust: only accept options.yml in QL tests

rust/extractor/src/config.rs

@@ -62,13 +62,7 @@ impl Config {
                 .ancestors()
                 // only travel up while we're within the test pack
                 .take_while_inclusive(|p| !p.join("qlpack.yml").exists())
-                .flat_map(|p| {
-                    [
-                        p.join("options"),
-                        p.join("options.yml"),
-                        p.join("options.yaml"),
-                    ]
-                })
+                .map(|p| p.join("options.yml"))
                 .filter(|p| p.exists())
                 .collect_vec();
             option_files.reverse();

rust/ql/test/query-tests/diagnostics/ExtractedFiles.expected

@@ -5,3 +5,4 @@
 | main.rs:0:0:0:0 | main.rs | File successfully extracted. |
 | my_macro.rs:0:0:0:0 | my_macro.rs | File successfully extracted. |
 | my_struct.rs:0:0:0:0 | my_struct.rs | File successfully extracted. |
+| options.yml:0:0:0:0 | options.yml | File successfully extracted. |

rust/ql/test/query-tests/diagnostics/LinesOfUserCodeInFiles.expected

@@ -5,3 +5,4 @@
 | lib.rs:0:0:0:0 | lib.rs | 5 |
 | does_not_compile.rs:0:0:0:0 | does_not_compile.rs | 3 |
 | error.rs:0:0:0:0 | error.rs | 3 |
+| options.yml:0:0:0:0 | options.yml | 0 |

rust/ql/test/query-tests/diagnostics/SummaryStats.expected

@@ -2,9 +2,9 @@
 | Elements unextracted | 0 |
 | Extraction errors | 0 |
 | Extraction warnings | 7 |
-| Files extracted - total | 7 |
+| Files extracted - total | 8 |
 | Files extracted - with errors | 2 |
-| Files extracted - without errors | 5 |
+| Files extracted - without errors | 6 |
 | Inconsistencies - AST | 0 |
 | Inconsistencies - CFG | 0 |
 | Inconsistencies - data flow | 0 |