chore(ci): switch to a custom fork of actions-rs/toolchain

This fork includes [actions-rs/toolchain#209][1], the PR that would add
support for TOML-style rustup toolchain files but has been left unmerged
for seven months.

[1]: actions-rs/toolchain#209

Author: yvt

.github/workflows/ci.yml

@@ -14,7 +14,8 @@ jobs:
         uses: actions/checkout@v2
 
       - name: Install Rust
-        uses: actions-rs/toolchain@v1
+        # FIXME: Switch back when actions-rs/toolchain#209 is merged
+        uses: r3-os/actions-rust-toolchain@patch/pr-209
         with:
           profile: minimal
           components: clippy, rustfmt
@@ -82,7 +83,8 @@ jobs:
         uses: actions/checkout@v1
 
       - name: Install Rust
-        uses: actions-rs/toolchain@v1
+        # FIXME: Switch back when actions-rs/toolchain#209 is merged
+        uses: r3-os/actions-rust-toolchain@patch/pr-209
         with:
           profile: minimal
 
@@ -123,7 +125,8 @@ jobs:
         uses: actions/checkout@v1
 
       - name: Install Rust
-        uses: actions-rs/toolchain@v1
+        # FIXME: Switch back when actions-rs/toolchain#209 is merged
+        uses: r3-os/actions-rust-toolchain@patch/pr-209
         with:
           profile: minimal
 
@@ -183,7 +186,8 @@ jobs:
         uses: actions/checkout@v1
 
       - name: Install Rust
-        uses: actions-rs/toolchain@v1
+        # FIXME: Switch back when actions-rs/toolchain#209 is merged
+        uses: r3-os/actions-rust-toolchain@patch/pr-209
         with:
           profile: minimal
 
@@ -258,7 +262,8 @@ jobs:
         uses: actions/checkout@v2
 
       - name: Install Rust
-        uses: actions-rs/toolchain@v1
+        # FIXME: Switch back when actions-rs/toolchain#209 is merged
+        uses: r3-os/actions-rust-toolchain@patch/pr-209
         with:
           profile: minimal
           components: rust-src
@@ -323,7 +328,8 @@ jobs:
         uses: actions/checkout@v2
 
       - name: Install Rust
-        uses: actions-rs/toolchain@v1
+        # FIXME: Switch back when actions-rs/toolchain#209 is merged
+        uses: r3-os/actions-rust-toolchain@patch/pr-209
         with:
           profile: minimal
           components: rust-src

.github/workflows/doc.yml

@@ -12,7 +12,8 @@ jobs:
         uses: actions/checkout@v2
 
       - name: Install Rust
-        uses: actions-rs/toolchain@v1
+        # FIXME: Switch back when actions-rs/toolchain#209 is merged
+        uses: r3-os/actions-rust-toolchain@patch/pr-209
         with:
           profile: minimal
 

.github/workflows/report-size.yml

@@ -35,7 +35,8 @@ jobs:
         uses: actions/checkout@v2
 
       - name: Install Rust
-        uses: actions-rs/toolchain@v1
+        # FIXME: Switch back when actions-rs/toolchain#209 is merged
+        uses: r3-os/actions-rust-toolchain@patch/pr-209
         with:
           profile: minimal
           components: rust-src