docs: remove obsolete option from pipewire aec (#416)

PipeWire no longer honors the 'method' option for the
echo-cancel module. Trying to use it will generate:

aec.method is not supported anymore use library.name

Remove it from all pipewire examples. It could be
replaced by 'library.name=aec/libspa-aec-webrtc',
but as that's currently the default (and only supported
option), I've elided it.

Co-authored-by: Omar Amin <65174210+omaramin-2000@users.noreply.github.com>

docs/enabling_aec.md

@@ -16,14 +16,13 @@ load-module module-echo-cancel source_name=aec_mic aec_method=webrtc
 
 ### PipeWire
 ```sh
-pw-cli load-module libpipewire-module-echo-cancel '{ aec.method=webrtc source.props={ node.name=aec_mic } }'
+pw-cli load-module libpipewire-module-echo-cancel '{ source.props={ node.name=aec_mic } }'
 ```
 
 To make permanent, add the following to the `context.modules` section of `/etc/pipewire/pipewire.conf`:
 ```
 { name = libpipewire-module-echo-cancel
     args = {
-      aec.method = webrtc
       source.props = { node.name = aec_mic }
     }
 }
@@ -34,7 +33,6 @@ Or if you are using a standard PipeWire installation without a custom `pipewire.
 context.modules = [
   { name = libpipewire-module-echo-cancel
     args = {
-      aec.method = webrtc
       source.props = { node.name = aec_mic }
     }
   }
@@ -57,14 +55,13 @@ pactl load-module module-echo-cancel source_name=aec_mic aec_method=webrtc sourc
 
 ### PipeWire
 ```sh
-pw-cli load-module libpipewire-module-echo-cancel '{ aec.method=webrtc source.props={ node.name=aec_mic node.description="Echo Cancelled Mic" } sink.props={ node.name=aec_sink } capture.props={ node.name=<your-mic-node-name> } playback.props={ node.name=<your-speaker-node-name> } }'
+pw-cli load-module libpipewire-module-echo-cancel '{ source.props={ node.name=aec_mic node.description="Echo Cancelled Mic" } sink.props={ node.name=aec_sink } capture.props={ node.name=<your-mic-node-name> } playback.props={ node.name=<your-speaker-node-name> } }'
 ```
 
 To make permanent, add to `context.modules` in `/etc/pipewire/pipewire.conf` or a file in `pipewire.conf.d/`:
 ```
 { name = libpipewire-module-echo-cancel
     args = {
-      aec.method = webrtc
       source.props = {
         node.name = aec_mic
         node.description = "Echo Cancelled Mic"