[RelEng] Update qualifier of o.e.help.webapp during release preparation

[HannesWell]

As noted in #2134 (comment), the o.e.help.webapp project currently needs a qualifier update during preparation of a new release cycle as the content of the generated jsp files changes then.
This extends the individual release preparation script for this repo do apply that update.

As it would be even better to avoid qualifier updates (and thus version updates), without content change I tried to investigate where the content of the differing generated files has changed. Comparing the class files respectively the java source files from which they are compiled, showed that for example org/eclipse/help/internal/webapp/jsp/advanced/advanced_jsp.java contains the following lines:

  private static java.util.Map<java.lang.String,java.lang.Long> _jspx_dependants;

  static {
    _jspx_dependants = new java.util.HashMap<java.lang.String,java.lang.Long>(1);
    _jspx_dependants.put("/advanced/header.jsp", Long.valueOf(1688504300120L));
  }

and the value put for the /advanced/header.jsp has changed.

But I don't know how that value is computed and how a change just because of a parent version change could be prevented?
If anybody has an idea and knows how we could enhance the build, please let me know, since I would be happy to avoid an enforced qualifier update.

[github-actions]

Test Results

 1 947 files  ±0   1 947 suites  ±0   1h 36m 48s ⏱️ - 2m 29s
 4 720 tests ±0   4 696 ✅ +1   24 💤 ±0  0 ❌  - 1 
14 160 runs  ±0  13 993 ✅ +1  167 💤 ±0  0 ❌  - 1 

Results for commit 9848b73. ± Comparison against base commit 8aa4a91.

[HannesWell]

But I don't know how that value is computed and how a change just because of a parent version change could be prevented?
If anybody has an idea and knows how we could enhance the build, please let me know, since I would be happy to avoid an enforced qualifier update.

Since nobody has a better idea until know, I'll continue with this. If somebody has a better idea later, I'm happy to have this reverted again.