Remove references to Erlang, move conda to end

Erlang isn't an external dep as it's included in the source tree.

Moved the conda warning to the end of the file.

For Google-fu, an example of the warning when using the incorrect `macdeployqt` from Anaconda was

```
Class QMacAutoReleasePoolTracker is implemented in both ...
```

Author: xavriley

BUILD-MAC.md

@@ -32,26 +32,14 @@ _These build instructions assume you're running under macOS 10.15+. If
 you're using an older version of macOS some steps may need
 modification._
 
-#### Anaconda users beware!
-
-Anaconda (a popular data science toolkit) installs a lot of extra programs, including one called `macdeployqt` which conflicts with the build you're about to try.
-
-If you run:
-
-```
-conda deactivate
-```
-
-Before the following steps that should stop things breaking. Once Sonic Pi is built, you can use `conda` as normal after that.
-
 ## 1. Installing Dependencies
 
 In order to build Sonic Pi's various components, we need to install a
 few dependencies:
 
 1. Xcode (12.1+) and command line tools
 2. Homebrew
-3. All other dependencies - Qt (5.15+), CMake (3.18+), Erlang (23.1.1+)
+3. All other dependencies - Qt (5.15+), CMake (3.18+)
 
 ### 1.1 Install Xcode
 
@@ -80,7 +68,7 @@ Once you have Homebrew installed, pulling in the rest of the
 dependencies is a couple of lines to execute within a terminal:
 
 ```
-brew install qt cmake erlang
+brew install qt cmake
 
 ```
 
@@ -157,6 +145,19 @@ directly either by double clicking it in the Finder or via the terminal
 
 ```
 
+#### Anaconda users beware!
+
+Anaconda (a popular data science toolkit) installs a lot of extra programs, including one called `macdeployqt` which conflicts with the build process mentioned above.
+
+If you run:
+
+```
+conda deactivate
+```
+
+Before the build steps that should stop things breaking. Once Sonic Pi is built, you can use `conda` as normal after that.
+
+
 ## Good Luck!
 
 Good luck and please share your new live coding adventure with us over on: