build(deps): bump org.scala-lang:scala-library from 2.12.20 to 2.12.21

[dependabot]

Bumps org.scala-lang:scala-library from 2.12.20 to 2.12.21.

Release notes

Sourced from org.scala-lang:scala-library's releases.

Scala 2.12.21

The Scala team at Akka is pleased to announce Scala 2.12.21.

This release is compatible with JDK 25 LTS and also introduces preliminary support for JDK 26.

The following are highlights of this release:

JDK 25 and 26 support

• Compiling on JDK 25 is now supported #11028
• Compiling on JDK 26 is also supported #11172
  • Note: compilation of Ordering subclasses (overriding min / max) may fail on Java 26, see [comment on #11175](scala/scala#11175)

New @uncheckedOverride annotation

The new @uncheckedOverride annotation is equivalent to the override keyword, except that it allows to override nothing. This is useful when cross-building: a method may override or not, depending on the version of some dependency. #11175

GPG key change

This release is signed with a different GPG key than previous Scala 2.12 releases. The new key is the same one used by Scala 3. #11158

More changes

For the complete 2.12.21 change lists, see all merged PRs and all closed bugs.

Compatibility

As usual for our minor releases, Scala 2.12.21 is binary-compatible with the whole Scala 2.12 series.

Contributors

A big thank you to everyone who's helped improve Scala by reporting bugs, improving our documentation, spreading kindness in discussions around Scala, and submitting and reviewing pull requests! You are all magnificent.

This release was brought to you by 9 contributors, according to git shortlog -sn --no-merges @ ^v2.12.20. Thank you Seth Tisue, Lukas Rytz, A. P. Marki, Friendseeker, Matthias Kurz, NthPortal, Philippus Baalman, Scala Steward, dependabot[bot].

Thanks to Akka for their continued sponsorship of the Scala 2 team’s efforts. Akka offers commercial support for Scala.

Scala 2.12 notes

The release notes for Scala 2.12.0 have important information applicable to the whole 2.12 series.

Obtaining Scala

Scala releases are available through a variety of channels, including (but not limited to):

• Bump the using scala setting in your Scala-CLI project
• Bump the scalaVersion setting in your sbt or Mill project
• Download a distribution from scala-lang.org
• Obtain JARs via Maven Central

Commits

• b7cc68a Merge pull request #11186 from lrytz/revert-ordering
• 1ddafac Revert "[backport] Tweak variance of Ordering.min and .max"
• f843123 Merge pull request #11185 from scala/dependabot/github_actions/2.12.x/actions...
• dbe2250 Bump actions/checkout from 5 to 6
• d092b1b Merge pull request #11183 from scala-steward/update/2.12.x/commons-lang3-3.20.0
• 5b69835 Update commons-lang3 to 3.20.0 in 2.12.x
• 597789e Merge pull request #11178 from dragos/dragos/backport-base-type-crash-fix
• 01ad07a Merge pull request #11175 from lrytz/t13127-12
• 7dcf3a6 Add @uncheckedOverride annotation for definitions that may override
• a70746c Prevent presentation compiler crash on base type cache invalidation
• Additional commits viewable in compare view

Most Recent Ignore Conditions Applied to This Pull Request

Dependency Name	Ignore Conditions
org.scala-lang:scala-library	[>= 2.13.a, < 2.14]
org.scala-lang:scala-library	[>= 3.a, < 4]

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[bestbeforetoday]

In addition to updating uses of Scala 2.12, this PR incorrectly changes uses of Scala 2.13 to 2.12.