Ignore Composer `/vendor` folder

[netweb]

Following #41057 a Composer /vendor folder might now exist, we should ignore it.

[johnbillion]

I'm going to add the vendor directory to the SVN ignored directories too.

[johnbillion]

In 42405:

Build/Test Tools: Instruct Git and Subversion to ignore Composer's vendor directory.

Props netweb
Fixes #42909

[netweb]

Replying to johnbillion:

I'm going to add the vendor directory to the SVN ignored directories too.

Thanks John, the svn:ignore was in 42909.diff​, Trac just doesn't render these patches terribly well ;)

[netweb]

As part of adding PHPCS to the 5.0 branch reopening and moving back to the 5.0 milestone

[netweb]

Patch 42909-50branch.diff​ for the 5.0 branch is ready for commit

Note: The patch includes the changes for svn:ignore, highly unlikely it will applied when applying the patch though.

To edit svn:ignore run svn propedit svn:ignore . from the command line and add vendor after jsdoc

Index: .
===================================================================
--- .   (revision 43735)
+++ .   (working copy)

Property changes on: .
___________________________________________________________________
Modified: svn:ignore
## -8,6 +8,7 ##
 node_modules
 npm-debug.log
 build
 wp-cli.local.yml
 .git
 jsdoc
+vendor

[netweb]

Patch 42909-50branch.diff​ is based on [42405] for backporting to the 5.0 branch

[SergeyBiryukov]

In 43748:

Build/Test Tools: Instruct Git and Subversion to ignore Composer's vendor directory.

Props netweb.
Merges [42405] to the 5.0 branch.
Fixes #42909.