3.0.0: Session layout

This major release drops support for old session layouts with keys in the document root. Sessions with these will be regarded invalid, users
will need to re-authenticate.

• Heads up: Dropped support for PHP < 7.4, see xp-framework/rfc#343
  (@thekid)
• Added support for MongoDB v3 - connecting lazily by default - @thekid
• Merged PR #9: Drop support for MongoDB v1 - @thekid

2.2.1: Substructure migration

• Correctly persist migrated substructure, fixing session modifications
  (@thekid)

2.2.0: New substructure

• Merged PR #8: Refactor document substructure, fixing issue #6 (handling
  of special characters . and $) while doing so.
  (@thekid)

2.1.0: XP 12 compatibility

• Made compatible with XP 12 - @thekid

2.0.0: Drop XP <= 9

• Implemented xp-framework/rfc#341: Drop XP <= 9 compatibility - @thekid
• Added PHP 8.4 to the test matrix - @thekid

1.3.0: Library compatibility

• Made this library compatible with xp-forge/mongodb 2.0.0 - @thekid
• Merged PR #5: Migrate to new testing library - @thekid

1.2.0: Index listing optimization

• Upgraded xp-forge/mongodb dependency to version 1.4.0, using read
  semantics for the listIndexes command
  (@thekid)

1.1.0: TTL index support

• Implemented #3: Support TTL indexes. Using these delegates removing
  expired sessions to the MongoDB server, speeding up session creation.
  See https://www.mongodb.com/docs/manual/core/index-ttl/
  (@thekid)

1.0.0: Production proven

The first major release was created after using this library in production
for more than two months.

• Merged PR #4: Add InMongoDB::gc() to run garbage collection - @thekid

0.4.1: Sessions library compatibilty

• Added compatibility with xp-forge/sessions version 3.0 - @thekid