gh-41128: Fix release github workflow
    
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Having numerical backends (coin, cplex, gurobi) packages have their own
versions is enough to fix the release github workflow.

This PR is a light alternative to #40840, which was stalled.

TEST: https://github.com/kwankyu/sage/actions/runs/19058005100

Test release with tarballs:
https://github.com/kwankyu/sage/releases/tag/100.2.beta4

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preview.

### ⌛ Dependencies

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URL: #41128
Reported by: Kwankyu Lee
Reviewer(s): Dima Pasechnik

Author: Release Manager

.github/workflows/changelog_trigger.yml renamed to .github/workflows/changelog-trigger.yml

@@ -1,4 +1,4 @@
-name: Trigger Changelog Generation
+name: Trigger changelog generation
 
 on:
   release:
@@ -8,7 +8,7 @@ jobs:
   trigger-website-repo-workflow:
     runs-on: ubuntu-latest
     steps:
-      - name: Trigger Generate Changelog Workflow in website repo
+      - name: Trigger Generate Changelog workflow in website repo
         if: "!github.event.release.prerelease"
         env:
           GITHUB_PAT: ${{ secrets.WEBSITE_ACCESS_TOKEN }}

.github/workflows/dist.yml renamed to .github/workflows/release.yml

@@ -1,4 +1,4 @@
-name: Prepare source distributions and wheels
+name: Release distributions and wheels
 
 on:
   push:

build/pkgs/sage_numerical_backends_coin/package-version.txt

@@ -0,0 +1 @@
+10.4

build/pkgs/sage_numerical_backends_coin/package-version.txt

@@ -0,0 +1 @@
+10.4

build/pkgs/sage_numerical_backends_cplex/package-version.txt

@@ -0,0 +1 @@
+10.4