Meta: Do not try to unzip the already decompressed WASM test suite .tar

WASM_SPEC_TEST_TAR_PATH actually refers to a tarball that has already
been decompressed with gzip, so running `tar -xzf` on it fails.

I introduced this mistake in 66582a875fd4494bfffeb6b59628ee52114f707e.

There is no need to keep an intermediary plain .tar file around, we can
pass the WASM_SPEC_TEST_GZ_PATH .tar.gz directly to `tar -xzf`.

Meta/CMake/wasm_spec_tests.cmake

@@ -6,7 +6,6 @@ if(INCLUDE_WASM_SPEC_TESTS)
     endif()
     set(WASM_SPEC_TEST_GZ_URL https://github.com/WebAssembly/testsuite/archive/refs/heads/main.tar.gz)
     set(WASM_SPEC_TEST_GZ_PATH ${CMAKE_BINARY_DIR}/wasm-spec-testsuite.tar.gz)
-    set(WASM_SPEC_TEST_TAR_PATH ${CMAKE_BINARY_DIR}/wasm-spec-testsuite.tar)
     set(WASM_SPEC_TEST_PATH ${SOURCE_DIR}/Userland/Libraries/LibWasm/Tests/Fixtures/SpecTests)
 
     if(NOT EXISTS ${WASM_SPEC_TEST_GZ_PATH})
@@ -22,9 +21,7 @@ if(INCLUDE_WASM_SPEC_TESTS)
     if(EXISTS ${WASM_SPEC_TEST_GZ_PATH} AND NOT EXISTS ${WASM_SPEC_TEST_PATH})
         message(STATUS "Extracting the WebAssembly testsuite from ${WASM_SPEC_TEST_GZ_PATH}...")
         file(MAKE_DIRECTORY ${WASM_SPEC_TEST_PATH})
-        execute_process(COMMAND "${GZIP_TOOL}" -k -d ${WASM_SPEC_TEST_GZ_PATH})
-        execute_process(COMMAND "${TAR_TOOL}" -xzf ${WASM_SPEC_TEST_TAR_PATH})
-        execute_process(COMMAND rm ${WASM_SPEC_TEST_TAR_PATH})
+        execute_process(COMMAND "${TAR_TOOL}" -xzf ${WASM_SPEC_TEST_GZ_PATH})
         file(GLOB WASM_TESTS "${CMAKE_BINARY_DIR}/testsuite-main/*.wast")
         foreach(PATH ${WASM_TESTS})
             get_filename_component(NAME ${PATH} NAME_WLE)