Rollup merge of #72569 - ChrisDenton:remove-innosetup, r=nikomatsakis

Remove legacy InnoSetup GUI installer

On Windows the InnoSetup `.exe` installer was superseded by the MSI installer long ago. It's no longer needed.

The `.exe` installer hasn't been linked from the [other installation methods](https://forge.rust-lang.org/infra/other-installation-methods.html#standalone) page in many years. As far as I can tell the intent was always to remove this installer once the MSI proved itself. Though admittedly both installers feel very "legacy" at this point.

Removing this would mean we only maintain one Windows GUI installer and would speed up the distribution phase.

As a result of removing InnoSetup, this closes #24397

.github/workflows/ci.yml

@@ -90,9 +90,6 @@ jobs:
       - name: install WIX
         run: src/ci/scripts/install-wix.sh
         if: success() && !env.SKIP_JOB
-      - name: install InnoSetup
-        run: src/ci/scripts/install-innosetup.sh
-        if: success() && !env.SKIP_JOB
       - name: ensure the build happens on a partition with enough space
         run: src/ci/scripts/symlink-build-dir.sh
         if: success() && !env.SKIP_JOB
@@ -193,9 +190,6 @@ jobs:
       - name: install WIX
         run: src/ci/scripts/install-wix.sh
         if: success() && !env.SKIP_JOB
-      - name: install InnoSetup
-        run: src/ci/scripts/install-innosetup.sh
-        if: success() && !env.SKIP_JOB
       - name: ensure the build happens on a partition with enough space
         run: src/ci/scripts/symlink-build-dir.sh
         if: success() && !env.SKIP_JOB
@@ -537,9 +531,6 @@ jobs:
       - name: install WIX
         run: src/ci/scripts/install-wix.sh
         if: success() && !env.SKIP_JOB
-      - name: install InnoSetup
-        run: src/ci/scripts/install-innosetup.sh
-        if: success() && !env.SKIP_JOB
       - name: ensure the build happens on a partition with enough space
         run: src/ci/scripts/symlink-build-dir.sh
         if: success() && !env.SKIP_JOB