Add tc358743-audio to boot config. (#86)

Resolves #74

### Notes
1. [Here's
confirmation](https://forums.raspberrypi.com/viewtopic.php?t=258742#p1577458)
that `dtoverlay=tc358743-audio` must be added to `/boot/config.txt` and
doesn't replace
[`dtoverlay=tc358743`](https://github.com/tiny-pilot/ansible-role-ustreamer/blob/d60cb4884f951cca4678421d9a8f3f8e993ff8cd/tasks/provision_tc358743.yml#L2-L7)
2. From the tasks description:
> We should use `when` conditions to ensure we don't add this to
Raspbian Buster.
    
I've maintained [this previous
decision](https://github.com/tiny-pilot/ansible-role-ustreamer/blob/d60cb4884f951cca4678421d9a8f3f8e993ff8cd/tasks/main.yml#L110-L117)
to simplify the conditions for supporting audio to Raspbian/Debian 11+
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Co-authored-by: Michael Lynch <[email protected]>

tasks/provision_tc358743.yml

@@ -6,6 +6,14 @@
     insertafter: EOF
   when: boot_config_exists | bool
 
+# Note that the tc358743-audio overlay depends on the tc358743 overlay.
+- name: enable TC358743-audio overlay in /boot/config.txt
+  lineinfile:
+    path: /boot/config.txt
+    line: "dtoverlay=tc358743-audio"
+    insertafter: EOF
+  when: boot_config_exists and ustreamer_enable_audio_streaming
+
 - name: set GPU memory to 256MB in /boot/config.txt
   lineinfile:
     path: /boot/config.txt

tasks/remove_tc358743.yml

@@ -12,3 +12,10 @@
     line: "dtoverlay=tc358743"
     state: absent
   when: boot_config_exists | bool
+
+- name: disable TC358743-audio overlay in /boot/config.txt
+  lineinfile:
+    path: /boot/config.txt
+    line: "dtoverlay=tc358743-audio"
+    state: absent
+  when: boot_config_exists | bool