deps/emscripten: Add support for dwp files in wasm builds (#39707)

Also, install before `proxy-wasm-cpp-sdk` to ensure it is used/patched

Currently its installed after, making our setup redundant

includes patch of emscripten-core/emsdk#1531

the context for this is that its required to use a hermetic llvm
toolchain (other than being generally useful)

without it, redundant hackery/patching would be required as the newer
platforms way of setting up toolchains expects _something_ to be setup
for various bins. Rather than adding a stub i figured add the fix. This
has historically been the main blocker to adding llvm toolchains, or
using the bazel platforms setup

Signed-off-by: Ryan Northey <ryan@synca.io>

Author: phlax

bazel/dependency_imports.bzl

@@ -42,6 +42,9 @@ def envoy_dependency_imports(go_version = GO_VERSION, jq_version = JQ_VERSION, y
     pip_dev_dependencies()
     pip_fuzzing_dependencies()
     rules_pkg_dependencies()
+    emscripten_deps(emscripten_version = "4.0.6")
+    register_emscripten_toolchains()
+
     rust_repository_set(
         name = "rust_linux_s390x",
         exec_triple = "s390x-unknown-linux-gnu",
@@ -66,8 +69,6 @@ def envoy_dependency_imports(go_version = GO_VERSION, jq_version = JQ_VERSION, y
         oss_fuzz = True,
         honggfuzz = False,
     )
-    emscripten_deps(emscripten_version = "3.1.67")
-    register_emscripten_toolchains()
     register_jq_toolchains(version = jq_version)
     register_yq_toolchains(version = yq_version)
     parser_deps()