patch 8.2.0713: the pam_environment file is not recognized

Problem:    The pam_environment file is not recognized.
Solution:   Add a filetype pattern for pamenv. (closes #6051)

runtime/filetype.vim

@@ -1133,6 +1133,9 @@ au BufNewFile,BufRead pf.conf			setf pf
 " Pam conf
 au BufNewFile,BufRead */etc/pam.conf		setf pamconf
 
+" Pam environment
+au BufNewFile,BufRead .pam_environment		setf pamenv
+
 " PApp
 au BufNewFile,BufRead *.papp,*.pxml,*.pxsl	setf papp
 

src/testdir/test_filetype.vim

@@ -322,6 +322,7 @@ let s:filename_checks = {
     \ 'openroad': ['file.or'],
     \ 'ora': ['file.ora'],
     \ 'pamconf': ['/etc/pam.conf'],
+    \ 'pamenv': ['/home/user/.pam_environment'],
     \ 'papp': ['file.papp', 'file.pxml', 'file.pxsl'],
     \ 'pascal': ['file.pas', 'file.dpr'],
     \ 'passwd': ['any/etc/passwd', 'any/etc/passwd-', 'any/etc/passwd.edit', 'any/etc/shadow', 'any/etc/shadow-', 'any/etc/shadow.edit', 'any/var/backups/passwd.bak', 'any/var/backups/shadow.bak'],

src/version.c

@@ -746,6 +746,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    713,
 /**/
     712,
 /**/