Fixes gh-19703

Closes gh-18953

* gh-20805:
  Polish "Split ConventionsPlugin into separate, more focussed classes"
  Split ConventionsPlugin into separate, more focussed classes

Closes gh-20805

See gh-20805

See gh-20805

Closes gh-20897

* gh-20799:
  Polish "Update endpoint enablement description to describe availability"
  Update endpoint enablement description to describe availability

Closes gh-20799

See gh-20799

See gh-20799

Closes gh-20888

Closes gh-20889

Closes gh-20678

This commit removes the duplication added temporarily in Spring Boot to
initialize a default WavefrontSender builder.

This commit also disables a test is failing at the moment, see
https://github.com/micrometer-metrics/micrometer/issues/1964

See gh-20854

Closes gh-20883

* pr/20874:
  Polish LayersIndex

Closes gh-20874

See gh-20874

Prior to this commit, processing of multiple properties files
discovered using a wildcard pattern would stop on any error
encountered while processing a file or when an empty properties file
was found, causing subsequent files from the pattern to be ignored.

This commit changes the behavior such that subsequent files are
processed on error or on an empty file.

Fixes gh-20873

This reverts commit 4e55f2aa.

This workaround is no longer required with the latest Micrometer
snapshot.

This commit works around a problem with deploying Boot apps to Wildfly
for integration testing while we investigate the root cause.

See gh-20876

Rename the SAML `singleSignOn` nested property to `singleSignOn` so
that we don't get problems when using uppercase environment variable
names.

See gh-20584

Remove the use of `Assert` since it's unavailable that early.

Closes gh-20875

Closes gh-20869

* pr/20832:
  Update copyright year
  Fix WebappLoader constructor deprecations

Closes gh-20832

See gh-20832

See gh-20832

Closes gh-20868

* pr/20847:
  Polish ConditionMessage#because()

Closes gh-20847

See gh-20847

Update `AbstractJarWriter` to ensure that streams are always closed,
even if entries are not written.