web: cleanup/loading attribute always true (#14288)

* web: Add InvalidationFlow to Radius Provider dialogues

## What

- Bugfix: adds the InvalidationFlow to the Radius Provider dialogues
  - Repairs: `{"invalidation_flow":["This field is required."]}` message, which was *not* propagated
    to the Notification.
- Nitpick: Pretties `?foo=${true}` expressions: `s/\?([^=]+)=\$\{true\}/\1/`

## Note

Yes, I know I'm going to have to do more magic when we harmonize the forms, and no, I didn't add the
Property Mappings to the wizard, and yes, I know I'm going to have pain with the *new* version of
the wizard. But this is a serious bug; you can't make Radius servers with *either* of the current
dialogues at the moment.

* This (temporary) change is needed to prevent the unit tests from failing.

\# What

\# Why

\# How

\# Designs

\# Test Steps

\# Other Notes

* Revert "This (temporary) change is needed to prevent the unit tests from failing."

This reverts commit dddde09be5.

* web: remove Lit syntax from always true attributes

## What

Replaces instances of `?loading=${true}` and `?loading="${true}"` with `loading`

## Why

The Lit syntax is completely unnecessary when the attribute's state is constant, and it's a few
(just a few) extra CPU cycles for Lit to process that.

More to the point, it annoys me.

## How

```
$ perl -pi.bak -e 's/\?loading=\$\{true\}/loading/' $(rg -l '\?loading=\$\{true\}')
$ find . -name '*.bak' -exec rm {} \;
$ perl -pi.bak -e 's/\?loading="\$\{true\}"/loading/' $(rg -l '\?loading="\$\{true\}"')
$ find . -name '*.bak' -exec rm {} \;
```

* Prettier had opinions

* Trigger Build

web/src/flow/providers/SessionEnd.ts

@@ -24,8 +24,7 @@ export class SessionEnd extends BaseStage<SessionEndChallenge, unknown> {
 
     render(): TemplateResult {
         if (!this.challenge) {
-            return html`<ak-empty-state ?loading="${true}" header=${msg("Loading")}>
-            </ak-empty-state>`;
+            return html`<ak-empty-state loading header=${msg("Loading")}> </ak-empty-state>`;
         }
         return html`<header class="pf-c-login__main-header">
                 <h1 class="pf-c-title pf-m-3xl">${this.challenge.flowInfo?.title}</h1>