chore: Release thin-vec version 0.2.13

chore: Release thin-vec version 0.2.12

chore: Release thin-vec version 0.2.11

(cargo-release) thin-vec version 0.2.10

(cargo-release) thin-vec version 0.2.9

0.2.7 release

* optimizes Clone and Extend
* adds optional serde feature

0.2.6 release

set_len now properly checks if we're using the empty singleton.
previous if you set_len on ThinVec::new() it would try to write
to a value in rodata and crash.

This is technically a soundness fix, although it almost certainly
was unexploitable.