It is not required, but you should put it, as a good practice.
That way, the day you need to add another instruction after this one, it’ll work fine.
And here is the manual’s page that answers your question : Instruction separation (quoting, emphasis mine) :
As in C or Perl, PHP requires instructions to be terminated with a semicolon at the end of each statement.
The closing tag of a block of PHP code automatically implies a semicolon; you do not need to have a semicolon terminating the last line of a PHP block.
The closing tag for the block will include the immediately trailing newline if one is present.