Update askama requirement from 0.15 to 0.16

[dependabot]

Updates the requirements on askama to permit the latest version.

Release notes

Sourced from askama's releases.

v0.16.0

This new release increases compatibility with jinja language, add support for more rust expressions in the templates. Take a look at the book for the migration guide.

(❗ = breaking change)

New features

• ❗Add support for let blocks by @​GuillaumeGomez in askama-rs/askama#697

• Implement compound assignments (e.g. {% mut a += 1 %}) by @​Kijewski in askama-rs/askama#685

• Add support for tuple, array and slice in type generics by @​GuillaumeGomez in askama-rs/askama#721

• Add support for macro args type annotations by @​GuillaumeGomez in askama-rs/askama#722

• Add support for caller() in variable declaration by @​GuillaumeGomez in askama-rs/askama#724

• Add glob support for dirs in config file by @​GuillaumeGomez in askama-rs/askama#731

Bugfixes

• Fix jinja macro arguments handling by @​GuillaumeGomez in askama-rs/askama#709
• parser: reject non-ASCII characters in byte literals by @​Kijewski in askama-rs/askama#694
• parser: reject syntaxes that could cause catastrophic backtracking by @​Kijewski in askama-rs/askama#695
• derive: make sure the size_hint is collected by @​Kijewski in askama-rs/askama#700
• Fix build determinism and macro path management by @​GuillaumeGomez in askama-rs/askama#710
• Correctly handle non-ident item in block error by @​GuillaumeGomez in askama-rs/askama#717
• Fix compiler error with recursive types on recursive templates by using dyn instead of plain generic bounds by @​GuillaumeGomez in askama-rs/askama#726
• Fix print = "code" by @​GuillaumeGomez in askama-rs/askama#729
• Switch to std::path::absolute to avoid symlinking template paths by @​kaepr in askama-rs/askama#720
• Fix askama template when called from within a macro in a different crate by @​GuillaumeGomez in askama-rs/askama#728

Other

• ❗Turn duplicated block warning into an error by @​GuillaumeGomez in askama-rs/askama#711

Performance

• Greatly speed up nested array parsing by @​GuillaumeGomez in askama-rs/askama#702

Documentation

• Add custom escaper example by @​GuillaumeGomez in askama-rs/askama#725
• Improve documentation for config by @​GuillaumeGomez in askama-rs/askama#732
• Document when Template trait methods can return Err by @​GuillaumeGomez in askama-rs/askama#730

Internal changes

• Limit recursions for Ty generics by @​GuillaumeGomez in askama-rs/askama#723
• Add regression test for temporary refs for #661 by @​GuillaumeGomez in askama-rs/askama#688
• Add complex-expression benchmark by @​Kijewski in askama-rs/askama#691
• Simplify Cargo.toml files by @​GuillaumeGomez in askama-rs/askama#696
• Clean compound implementation by @​GuillaumeGomez in askama-rs/askama#699
• Update rand+rand_xoshiro dev-dependencies by @​Kijewski in askama-rs/askama#701

... (truncated)

Commits

• 229e8bb Merge pull request #733 from GuillaumeGomez/update
• d8073f7 Add migration guide for 0.15 to 0.16 upgrades
• 1d49957 Update packages version to 0.16.0
• 9444439 Merge pull request #732 from GuillaumeGomez/improve-docs
• 7749af6 Improve documentation for config
• 46fa7ba Merge pull request #731 from GuillaumeGomez/glob-support
• 546e082 Add glob support for dirs in config file
• d992acf Merge pull request #730 from GuillaumeGomez/add-err-docs
• ecc11d6 Update ui tests stderr for new rust version
• 7098c6f Fix new clippy lint
• Additional commits viewable in compare view

Dependabot will resolve any conflicts with this PR as long as you don't alter it yourself. You can also trigger a rebase manually by commenting @dependabot rebase.

---

Dependabot commands and options

You can trigger Dependabot actions by commenting on this PR:

• @dependabot rebase will rebase this PR
• @dependabot recreate will recreate this PR, overwriting any edits that have been made to it
• @dependabot show <dependency name> ignore conditions will show all of the ignore conditions of the specified dependency
• @dependabot ignore this major version will close this PR and stop Dependabot creating any more for this major version (unless you reopen the PR or upgrade to it yourself)
• @dependabot ignore this minor version will close this PR and stop Dependabot creating any more for this minor version (unless you reopen the PR or upgrade to it yourself)
• @dependabot ignore this dependency will close this PR and stop Dependabot creating any more for this dependency (unless you reopen the PR or upgrade to it yourself)

[dependabot]

OK, I won't notify you again about this release, but will get in touch when a new version is available. If you'd rather skip all updates until the next major or minor version, let me know by commenting @dependabot ignore this major version or @dependabot ignore this minor version. You can also ignore all major, minor, or patch releases for a dependency by adding an ignore condition with the desired update_types to your config file.

If you change your mind, just re-open this PR and I'll resolve any conflicts on it.