sysutils/flowgger: Update to 0.2.9

This also unbreaks the build with rust-nightly:
error[E0214]: parenthesized type parameters may only be used with a Fn trait

--> /wrkdirs/usr/ports/sysutils/flowgger/work/flowgger-0.2.6-28-gab572a0/cargo-crates/twox-hash-1.1.0/src/number_streams.rs:67:23
 |

67 | fn count(self) -> usize() {

|                       ^^^^^^^ only `Fn` traits may use parentheses

...
74 | number_stream!(U32FromBytes, u32, U32_BYTES);

| --------------------------------------------- in this macro invocation

error[E0214]: parenthesized type parameters may only be used with a Fn trait

--> /wrkdirs/usr/ports/sysutils/flowgger/work/flowgger-0.2.6-28-gab572a0/cargo-crates/twox-hash-1.1.0/src/number_streams.rs:67:23
 |

67 | fn count(self) -> usize() {

|                       ^^^^^^^ only `Fn` traits may use parentheses

...
75 | number_stream!(U64FromBytes, u64, U64_BYTES);

| --------------------------------------------- in this macro invocation

error: aborting due to 2 previous errors

• Take it back
• Upstream repo is now awslabs/flowgger
• Switch to crates.io since releases are no longer tagged on GitHub
• Update WWW