Closes gh-9073

Calling launch of PropertiesLauncherTests sets the thread context
class loader to an instance of LaunchedURLClassLoader. To avoid this
class loader being used beyond the scope of the test and launcher
that created it, this commit updates PropertiesLauncherTests to
capture the TCCL before each test and restore it after each test.

Closes gh-9378

Closes gh-9346

Those properties are no longer honoured with Atomikos 3.8 and we're
using 3.9 by default.

Closes gh-9292

This commit makes sure to unwrap any transaction aware cache before
collecting metrics for them.

Closes gh-8984

See gh-9280

Previously, when the liquibase.url, .username, and .password
properties were used to configure a DataSource specifically for
Liquibase that DataSource would never be explicitly closed. As it is
created by DataSourceBuilder with no explicitly configured type it
will use whichever connection pool is available and, therefore, will
create and keep open the pool's minimum number of connections. This
is an unnecessary use of resources both in the application and in the
database.

This commit updates LiquibaseAutoConfiguration so that if it uses
DataSourceBuilder to create a DataSource then it will also close that
DataSource once the database has been migrated.

Closes gh-9218

* pr/9212:
  Fix typo in javadoc

Closes gh-9212

Closes gh-9178

Closes gh-9177

Closes gh-9176

Closes gh-9175

Closes gh-9171

Closes gh-9082

See gh-9080

Closes gh-9080

Closes gh-9080

Closes gh-9075

* pr/9065:
  Polish "Clarify and re-organize docs on caching"
  Clarify and re-organize docs on caching

Closes gh-9065

See gh-9065

CachePublicMetrics wasn't explicitly tested and was still using field
injection. This commit improves the situation in preparation of the fix
for gh-8984

Closes gh-8983

Closes gh-9040

Closes gh-9039

Closes gh-9038

Closes gh-9037

Closes gh-9036

Closes gh-9035

Closes gh-9034

Closes gh-9033

`BasicErrorControllerIntegrationTest` is handling the context in each test
and yet it starts a useless test via `@SpringBootTest`. This commit
removes the useless runner and associated annotations.