Fix filename uniqueness when using TempfileTask

[jawira]

I have noticed that filenames generate by TempfileTask are not unique when they are called multiple times at high frequency.

For example, given the following target:

<target name="tempfiles">
  <tempfile property="file1"/>
  <tempfile property="file2"/>
  <tempfile property="file3"/>
  <tempfile property="file4"/>
  <tempfile property="file5"/>
  <tempfile property="file6"/>
  <tempfile property="file7"/>
  <tempfile property="file8"/>
  <echo>${file1}</echo>
  <echo>${file2}</echo>
  <echo>${file3}</echo>
  <echo>${file4}</echo>
  <echo>${file5}</echo>
  <echo>${file6}</echo>
  <echo>${file7}</echo>
  <echo>${file8}</echo>
</target>

This is going to be the output:

$ phing tempfiles
Buildfile: /home/jawira/PhpstormProjects/dummy/build.xml

Phing Cookbook > tempfiles:

     [echo] /home/jawira/PhpstormProjects/dummy/1107b2f8
     [echo] /home/jawira/PhpstormProjects/dummy/1107b2f8
     [echo] /home/jawira/PhpstormProjects/dummy/1107b2f8
     [echo] /home/jawira/PhpstormProjects/dummy/1107b2f8
     [echo] /home/jawira/PhpstormProjects/dummy/1107b2f8
     [echo] /home/jawira/PhpstormProjects/dummy/1107b2f8
     [echo] /home/jawira/PhpstormProjects/dummy/1107b2f8
     [echo] /home/jawira/PhpstormProjects/dummy/1107b2f8

BUILD FINISHED

Total time: 0.0428 seconds

As you can see all filenames are identical, the reason is that current implementation uses time() function as seed for filename generation, which only has second-level precision.

I fix this issue replacing time() with microtime().

[codecov]

Codecov Report

Attention: Patch coverage is 50.00000% with 1 line in your changes missing coverage. Please review.

Project coverage is 53.31%. Comparing base (0493a46) to head (ea49f9b).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
src/Phing/Io/FileUtils.php	50.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff            @@
##               main    #1917   +/-   ##
=========================================
  Coverage     53.30%   53.31%           
  Complexity     9797     9797           
=========================================
  Files           495      495           
  Lines         24639    24639           
=========================================
+ Hits          13135    13136    +1     
+ Misses        11504    11503    -1     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.