[CI] Change order of arguments to signtool.exe.

[NlightNFotis]

According to the documentation at https://docs.microsoft.com/en-us/dotnet/framework/tools/signtool-exe,
any options should be coming before the file_name, denoting the file
to be signed.

This should stop the options being seemingly ignored, and causing issues
during the release process.

• Each commit message has a non-empty body, explaining why the change was made.
• Methods or procedures I have added are documented, following the guidelines provided in CODING_STANDARD.md.
• The feature or user visible behaviour I have added or modified has been documented in the User Guide in doc/cprover-manual/
• Regression or unit tests are included, or existing tests cover the modified code (in this case I have detailed which ones those are in the commit message).
• My commit message includes data points confirming performance improvements (if claimed).
• My PR is restricted to a single feature or bugfix.
• White-space or formatting changes outside the feature-related changed lines are in commits of their own.

[codecov]

Codecov Report

Merging #6358 (af09077) into develop (9d774a7) will decrease coverage by 0.00%.
The diff coverage is 100.00%.

❗ Current head af09077 differs from pull request most recent head 14553de. Consider uploading reports for the commit 14553de to get more accurate results

@@             Coverage Diff             @@
##           develop    #6358      +/-   ##
===========================================
- Coverage    75.90%   75.90%   -0.01%     
===========================================
  Files         1515     1515              
  Lines       164002   164004       +2     
===========================================
+ Hits        124482   124483       +1     
- Misses       39520    39521       +1     

Impacted Files	Coverage Δ
src/goto-analyzer/unreachable_instructions.cpp	90.95% <100.00%> (-0.42%)	⬇️

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