VPR-217 fix(deploy): raise the ANCM shutdownTimeLimit off its 10s default

[rlorenzo]

• The module's own timeout is a separate setting from the app pool's
  shutdownTimeLimit, and its 10s default undercut both links VPR-188
  pinned, inverting the chain on app_offline.htm deploys
• Needs a source web.config because no MSBuild property reaches it; the
  SDK transform fills in the rest at publish time

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[codecov-commenter]

Bundle Report

Bundle size has no change ✅

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 45.37%. Comparing base (eb54f77) to head (cac12e6).
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@                           Coverage Diff                            @@
##           feature/VPR-188-hangfire-shutdown-chain     #346   +/-   ##
========================================================================
  Coverage                                    45.37%   45.37%           
========================================================================
  Files                                          949      949           
  Lines                                        49547    49547           
  Branches                                      6703     6703           
========================================================================
  Hits                                         22484    22484           
  Misses                                       26096    26096           
  Partials                                       967      967           

Flag	Coverage Δ
backend	42.34% <ø> (ø)
frontend	64.68% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
web/Classes/Scheduler/HangfireExtensions.cs	0.00% <ø> (ø)