Remove duplicate statement in tracer-config test

The tracer-config.test.js file contained a duplicate of the statement:

  process.env["SEMMLE_DEPTRACE_SOCKET"] = "abc";

one line apart. This removes the second instance of this statement.

src/tracer-config.test.ts

@@ -64,7 +64,6 @@ test("getTracerConfigForLanguage - existing / critical vars", async (t) => {
     process.env["SEMMLE_COPY_EXECUTABLES_ROOT"] = "abc";
     process.env["SEMMLE_DEPTRACE_SOCKET"] = "abc";
     process.env["SEMMLE_JAVA_TOOL_OPTIONS"] = "abc";
-    process.env["SEMMLE_DEPTRACE_SOCKET"] = "abc";
     process.env["CODEQL_VAR"] = "abc";
 
     // Now CodeQL returns all these variables, and one more, with different values