elliptic-curve: minimum supported tap for bits is v1.0.1 (#1355)

...when resolving with `-Z minimal-versions`

`tap` is a transitive dependency of `bitvec` by way of `wyz` v0.5, which
misspecifies the required `tap` version. This is addressed in newer v0.6
releases of `wyz`, which `bitvec` does not yet use.

So, as a workaround, this adds an explicit `dep:tap` dependency on
v1.0.1 for the `bits` feature.

This was the last remaining `minimal-versions` incompatibility in this
crate, allowing all features to now be tested in the `minimal-versions`
check in CI.

.github/workflows/elliptic-curve.yml

@@ -67,7 +67,7 @@ jobs:
  toolchain: nightly
  - uses: RustCrypto/actions/cargo-hack-install@master
  - run: cargo update -Z minimal-versions
- - run: cargo build --release --features ecdh,hash2curve,jwk,pem,std,voprf # TODO(tarcieri): test all features
+ - run: cargo +stable build --release --all-features
 
  test:
  runs-on: ubuntu-latest

elliptic-curve/Cargo.toml

@@ -35,6 +35,7 @@ pkcs8 = { version = "0.10.2", optional = true, default-features = false }
 sec1 = { version = "0.7.1", optional = true, features = ["subtle", "zeroize"] }
 serdect = { version = "0.2", optional = true, default-features = false, features = ["alloc"] }
 serde_json = { version = "1.0.47", optional = true, default-features = false, features = ["alloc"] }
+tap = { version = "1.0.1", optional = true, default-features = false } # hack for minimal-versions support for `bits`
 
 [dev-dependencies]
 hex-literal = "0.4"
@@ -59,7 +60,7 @@ std = [
 ]
 
 arithmetic = ["group"]
-bits = ["arithmetic", "ff/bits"]
+bits = ["arithmetic", "ff/bits", "dep:tap"]
 dev = ["arithmetic", "dep:hex-literal", "pem", "pkcs8"]
 hash2curve = ["arithmetic", "digest"]
 ecdh = ["arithmetic", "digest", "dep:hkdf"]